"A practical man can always make what he wants to do look like a noble sacrifice of personal inclinations to the welfare of the community. I've decided that I've got to be practical myself, and that's one of the rules. How about breakfast?" The Pirates of Ersatz, Murray Leinster
From your question I noticed a few things. Nominally, I completely agree with @mxyzplk's answer, so this should be in the way of an addendum.
It sucks to be the leader
In a RPG, it just completely sucks to be the leader. Most players when confronted with a plan, remember about fifteen percent of it for the first fifteen minutes. But they'll certainly remember when you deviate. Leaders get no additional responsibility and no perquisites, but they get all the blame.
In the military this is mitigated with the clear distinction between commissioned and non-commissioned officers. Not least because the isolation provides both support structures and necessary emotional distance (to a degree, of course). Being "elected" leader, especially with the pack dynamics of typical werewolf games is an extremely dubious honour that I'd flatly reject.
The fact that while you may be leader in character but not dominant over the player group makes things even stickier. You need to assert authority within the realm of the narrative without actually having that authority in reality. Again, something that will cause friction and resentment any way you cut it.
Depressing environments bleed emotions into play
The world of darkness does what it says on the tin. Having played in a horror game myself recently, the iconic themes of the world of darkness do not make for "happy" or, for that matter, validating game experiences in the main. (And, if they do, it's a violation of genre.) When you are faced with the stresses of being "leader" which are compounded by the stressors of the philosophies baked into the setting, no wonder you're having a rough time.
Some solutions:
On leadership:
Fundamentally, a gaming group is a relationship. Bad relationships that do not provide validation are a drain on mental and emotional resources. When they don't work, cut them off or change them. In your case, I'd play a game that's a bit lighter in tone and focus: a nice traditional dungeon crawl or similar heroic fantasy.
I'd also reject the leader role for all the reasons I outlined above. Or, if they force it upon you, demand the perquisites and authority that is concomitant with it: they can't have it both ways.
On the group:
I've found that group character creation creates a far more cohesive group. By having entangled backstories, the group can draw upon a deeper understanding of each others' characters, creating the basis for empathy and respect within the characters, instead of the necessary simulacrum imposed by players.
By articulating desired tropes, a "palette" (as Microscope) calls it, before the game begins, you'll be able to shape the narrative of the group in directions that you want to play. This allows you to avoid the nominally depressive tropes that come default with the setting (not limited to world of darkness) and describe a source for future characters to connect with the current group. Replacement characters, if they tie into the shared narrative, will continue to maintain the tropes and social trust.
Be practical:
As players, we shape our narratives to an amazing degree. Emulate Bron Hoddan in the Pirates of Ersatz. While playing, you will be aware of the desired practical outcome that will provide validation and satisfy your personal goals. With that outcome in mind, you then frame it in terms that suit both your character's narrative and the expected narratives of the other players such that they will act to reinforce your framing and thereby your outcome. If you fight their narrative control by "being a loner," it is difficult to achieve your own goals. If you help them work as a team and appear to sacrifice nobly on their behalf while executing your own goals... the entire process is smoother and more effective.
Note that I am not saying to lie. Instead, consider the causal constructions of your actions, the explanations for those actions to be an aspect of the role * separate* from the actions themselves. By manipulating the framing as well as the actions, you can provide the necessary hooks for the other players to support your version of reality, rather than rejecting it and, by extension, you.
Postscript
Looking at your comments to other questions, you should absolutely give this group two last tries. In the first trial (of one or two games), try a heroic romp where you can be "Big Damn Heroes." Require the players who need the spotlight be leader. In the second trial (again of one or two games), try a game where players can intrigue against each other (I'd recommend Ars Magica, but then again I recommend it for most things. Most games support PvP intrigue quite ably.) If neither game provides the validation you need and the spotlight the other players need, move on. Before you do anything, take a month break, sit down, relax, and try to game with some strangers. I'm pretty sure that if you go looking for games in the chat section of this site... someone will oblige. For more on the framing problem, I'd quite recommend Rule 34 by Stross, as it describes it in a delicious narrative context.
Yes, but... try asking for a verbal player summary at the end each session and a recap at the beginning of the next.
I've used this technique with my players in several campaigns, ever since it became apparent to me that players will find things interesting that you as the GM did not expect and they will sometimes interpret or recall material differently than you as the GM intended or thought you conveyed. My suggestion is that this is a better solution than asking for their notes.
At the end of each session, ask your players to verbally summarize what occurred during the session. They might find this a little strange at first, but if you just explain to them one time what the purpose is (so that you can audit what information got across from the GM to the players to help improve the player experience) they will, in my experience, buy into it. This helps you prepare for the upcoming session by focusing on what they like.
Then at the start of the next session, ask your players for a verbal recap from last time. They will tend to forget about things that they didn't consider especially interesting or important. Whatever they do recall, it stuck with them enough that you should probably focus on those topics during the current session. Also, if there are important things they fail to recap, you can easily use some simple exposition to remind them of what they may have forgotten. This helps you keep the current session on track and maximize player comprehension.
If they mention things that you already intended for them to pay careful attention to or things that you considered important, then don't bother writing those things down, because you already know them. If they review something that you had not considered important or if they interpreted information or events differently than you did, write down just enough for you to be able to incorporate those ideas into the remainder of the session or into the next session. (And if some players are paranoid and think they've got everything all wrong whenever they see you write something down... take notes no matter what they say, or make it clear that you're not writing down gotchas to try to trip them up later.)
With this technique, you don't need to ask players to show you their notes. In my experience, this makes them feel less like they are being judged or graded on accuracy. It also clearly identifies for you what they thought was important in the grand scheme, not what they might have thought was important when they were jotting it down. In other words, the information they will tell you is a more accurate representation of their intrigue than what their notes include.
To avoid stressing players who don't like this sort of thing, don't make it compulsory to participate in the summary or recap. Make it an optional thing for those sorts of players who enjoy it and want to participate voluntarily.
Depending on the kind of game you're playing, it's easy to incentivize these activities, too, by giving the player who provides the most informative recap some sort of one-use perk or boon for the session, depending on the rules for the system you are playing. For example, in D&D 5e I give Inspiration, in 13th Age I give a free icon relationship re-roll, and in Freeform/Universal or Fate I give hero points. Most games have something equivalent you can provide as a reward to give attentive players a motivation for participating in the summary or recap.
Best Answer
There are a ton of issues with that.
That doesn’t automatically mean it’s the wrong move, just that it’s fraught with problems.
Ultimately, most people feel that roleplaying works best when everyone, ya know, plays a role. As in, behaves as their character would, based on what their character knows, rather than how they would, based on what they know. This is usually the goal.
However, most groups don’t explicitly enforce it. It’s considered bad taste to meta-game, it’s considered good roleplaying to stay in character even when it hurts, but there aren’t specific rules about it, and in many groups the DM claiming “your character wouldn’t do that” is a gross violation of the player’s area of control (i.e. their character). Statements to that effect have been reasons to leave a group for a lot of players in a lot of situations, and while I am lucky to have never played under a DM who seriously thought that was his business, if I were I most likely wouldn’t tolerate it.
But your group may be different. You are expressing frustration with the status quo, and that is presumably a feeling shared by others. This could be a solution to that, and ideally the questioning would come more as a reminder than as any real attempt to control others’ characters.
That said, the objections of some people in your group suggests that not everyone feels the way you do. There are people in the group who either A. feel they are not metagaming, or B. feel that the metagaming is a good thing, and in both cases there is not a problem. Both perspectives are valid, though B is a bit unusual. (There is a third option, C, wherein people recognize that there is a problem but dislike this solution; I would probably fall in that category. That said, these people are probably already doing their best not to metagame.)
So what you really need to do is discuss metagaming, what is or isn’t and how much is or isn’t appropriate. You need to have a mature discussion, and you need to listen to others’ opinions, perspectives, and preferences. More than likely, no two people in the group will exactly align, but hopefully everyone will be near enough to some common ground that a compromise can be made.
And once you have that, you really probably don’t need this rule. You might include it, in theory, if people felt they needed to be reminded or “called on” for metagaming, but I really cannot imagine any point where it is a good idea for a DM to say “no, your character would not do that.” You can question an action (though even that might be disrespectful), but ultimately the DM has to back down there because his authority, so absolute otherwise, cannot control player characters like that, or else the players have nothing and there is no game.
Under no circumstances should this rule be even considered unless everyone wants it. A group that agreed it would be for the best to get called in this fashion could work. But if some do, and some don’t, it is not a reasonable thing for a DM to expect of players. The individuals who requested it could get called on it, but you should never tell someone he’s not playing his character right, after he’s specifically told you to stay hands-off on that subject. Were it me, I would walk out the very first time it happened, assuming you convinced me to stay at all, which I tend to doubt.
There can still be a compromise even if people object to this as a rule, of course; that’s actually normal for most groups. E.g. if you say something like “I won’t call you on it, but it is your responsibility to avoid metagaming and this game isn’t going to survive if you don’t.” and he says “OK, I will do what I can,” that is a workable situation.
But if no compromise can be made, if some feel that their behavior is entirely appropriate and refuse to modify it, and you feel your expectations are entirely reasonable and refuse to modify those, then you have learned this without going through it the hard way: you are not a compatible group of people who are looking for the same game. That’s pretty much what you’d discover if you tried to “enforce” these rules without a compromise, but there’d be a lot more ill feelings. Better to skip that step.