It's pretty reasonable you're annoyed. One of your fellow players secretly plotted to kill your character for revenge (and it worked), the DM - the one guy you pretty much have to be able to trust - was in on it, and your fellow players offered you no emotional support at a point when you clearly needed it and instead made things worse for you.
People have been annoyed over character deaths, but you also have the issue of a betrayal of trust.
Different groups (and different DMs) handle stuff like this in very different ways - some handle it well, some badly. You had a conflict within the party, and a conflict between two people, and some character death and secret plots on your hands. These are often things groups don't talk about beforehand, but should. As the DM, I wouldn't have allowed this secret plot and would've talked to you two outside the game to get this enmity settled at first signs.
(And honestly, if this was real out-of-game racism you were experiencing, I wouldn't have tolerated that either.)
So now the guy who betrayed you is the DM and you want revenge.
Don't do it.
A good plan is to decline the invitation, not play, leave, and find something else to do or another D&D group to play with. This is not advice for how to ruin Bob's day. This is advice for how to avoid having your own next two months ruined, and possibly several weeks or months after that as well, and instead have some degree of peace for yourself.
You're pissed off. But, proverbially:
Holding onto anger is like drinking poison and waiting for the other person to die.
— (Not sure who first said this)
So you're going to have several gaming sessions and two months in which you're busy being pissed off at Bob, stressed out working out how to get revenge, and suffering over the lot of it - and expecting him to suffer for it. Eventually. At some point. Maybe.
That's not working out in your benefit.
Here's how the next two months are going to pan out according to this plan.
- Bob's the DM. The universe of the game you're considering bends to his whims.
- He doesn't like you to begin with, resents you for something you did to him, and apparently is subtly vengeful. He might give you a hard time for the next two months. This is going to feed right back into you being even unhappier in general, and unhappy to be in that game. This may even increase the degree of revenge you want, something you might not even get to begin with.
- You're going to be preoccupied being annoyed at him and not really actually just enjoying a good game of D&D. (Not that this game is going to be a good game of D&D for you necessarily anyway.)
- Eventually, you might actually find a way to get back at him. But, since he's the absolute controller of the game's universe, he can just say: "Oh. Well, my guy's goddess smiles upon him and heals him. Then she teleports your character into the plane of fire. Alright, whose turn next?"
- Or you don't get anything out of it and you're just annoyed.
- Or a month in, before anything even really happens, he or your fellow players ask you to leave because you're not being very fun to play with. You probably won't be. You're here for revenge, not to enjoy a good game.
- And you're playing with this guy as your DM the whole time, again. That's worth repeating. Why would you want that?
This entire plan is toxic to you and you alone. It's going to be really unpleasant for you, and more likely than not won't get anything out of it - and if you do, it probably won't be very satisfying.
Don't do it.
But I really want revenge!
This is an issue between you and another person, not an issue D&D will help with. Don't try to solve it through D&D, and don't try to solve it by playing with this guy as a DM for a few months.
Deal with it out of the game somehow. Maybe talk to him and get stuff off your chest. Consider walking away and leaving it behind you rather than let this weigh on you. Different things work for different people. I don't know what will work for you, personally. But spend these two months of your life doing something else. Find peace, somehow.
A surprising option is forgiving him - and not for his benefit, but for yours. Forgiveness is just as often so you can stop holding onto the negative emotions you have - the ones which are affecting you much more than anyone else - and let them go and find some inner peace. You might not be prepared to do that, but I advise you try it.
D&D is normally not like this.
(But sometimes it can be.)
There are going to be groups more supportive of first time players. There are going to be groups where you can genuinely be friends with most people, get along with all of them, and reliably trust the DM and your fellow players. This wasn't one of them, clearly. I suggest you find a group that suits you if you want to keep playing D&D.
One thing that normally goes unrecognised is that several D&D players at the same table, playing the same session at the same time, are usually not even playing the same game. They have different expectations of what a good game constitutes, different ideas of what's OK and what's not, different understandings of the rules, and different opinions over how issues like loot and character death should be handled. Usually, they assume that everyone else shares a similar view, without realising that everyone probably thinks very differently - to each other, as well.
An analogy is having several people sitting around a table to play a game of cards, but they are playing different games: one person is playing Poker, another Hearts, and another Go Fish. That wouldn't work very well, but somehow that's how D&D gets played without anyone realising it.
This disconnect is the reason why someone authored the Same Page Tool - which, as its name suggests, exists to get people on the same page. Its author also wrote about The Roots of the Big Problems and A Way Out (from which I drew the card game analogy). All three of these links discuss this issue and the situations that arise from it, and how to deal with them.
This group was not on the same page as you, and were not what you were after. Another group might be.
The best way to handle attention-hogging "diva" players is to set limits, then enforce them.
Set Limits
Divas, whether in RPG groups or in real life, take advantage of the social expectation to be polite and accomodating in order to get away with their behavior. So to protect your own sanity and your game, you need to create an alternate social expectation up front. In the case of a play-by-post RPG, this could mean rules like "if you take longer than X days to post your actions, the GM will declare a neutral action for you and continue without you", and "if you're repeatedly unable to come up with actions or ideas for your character, the GM may ask you to create a new one you're more comfortable playing."
The key here is to set the limits as a group. Don't single out the diva (they'll probably feel singled out anyway, but that's beside the point), just take some time before or during the opening of the game to state these ground rules. Emphasize that they apply to everybody and that they will be enforced in order to keep the game running smoothly for all players.
Enforce Those Limits
An important part of setting limits is declaring how those limits will be enforced. Otherwise it's like a parent who says to their toddler, "You'd better get over here right now! I mean it! Now!" but never actually takes action to address non-compliance. The toddler knows she can ignore the warnings because nothing will happen to her if she does, and she gets to keep doing whatever she's doing anyway.
Therefore, once you've set your limits for the game, enforce them. If the diva player (or any other player) takes too long to post their actions, do as you said: declare a neutral action for them, then move on. Ignore whining and complaining; refer back to the limits established at the beginning of the game: "I understand you're frustrated. You agreed to the limit of X days at the beginning of the game, and it's been X days, so I had to move on for the sake of the rest of the players."
It's perfectly fair to give warnings (such as a message a day before the deadline saying "Hey, you agreed to post within X days and it's been X-1 days. Just wanted to give you a heads-up!"). However, the important part is enforcing the limit after it's been broken, and doing so consistently and calmly.
Keeping Your Own Sanity
Divas thrive on getting attention, whether positive or negative, from others. Setting and enforcing limits helps take away a lot of their avenues for getting this attention. They'll try to get it back by throwing tantrums, complaining, and otherwise table-flipping over the "unfair" rules and "getting picked on". This is why it's so important to set the limits for everyone at the beginning of the game. That way all you have to do is calmly and repeatedly fall back on, "You agreed to these rules. That's all there is to it." As long as you keep your calm and ignore the diva's attention grabs (and make sure the other players don't get drawn in), you'll remove the diva's incentive to act that way and make the game more enjoyable for everyone.
Note that this may result in the diva threatening to leave the group. If they do, say calmly, "it's your choice whether to leave or stay. If you stay, these are the rules you've agreed to." Then it's up to them whether to leave (and get no attention at all) or stay (and get less attention than they'd like, but still some). If they do actually leave, just say, "Thanks for gaming with us" and let them go. The point here is to not give them any attention, since that's what they're after. Giving them attention in response to threats or flouncing only reinforces that they can get what they want by doing these things. So just stay calm, be polite, and let the diva figure out that their bad behavior is no longer going to get them anywhere.
Best Answer
I recommend a piña colada and warm sunny beach
You, my friend, have some angsty players. You're clearly not enjoying running games for them and are burned out. Nothing good can come from trying to keep things moving forward.
It sounds like there's just too much friction between the players to make things work, so let the players know that you need a break.
You can let them know that you're tired of the interpersonal drama in a way that doesn't come across as accusatory or confrontational. This is tricky to do and your wording/approach will need to be tailored for your players. One tip that I've found helps me when I have to have meta talks with players is to speak about how you feel, rather then telling them that they are in the wrong. Instead of telling them "Your remarks are causing others to feel attacked" say "I feel like I'm having to act as an intermediary for personal disputes too much. That's not fun for me."
Now, if your goal was to try and make things continue to work, I would say your next line might be something like "I want to ask each of you to help out on that and think about how a remark might be misconstrued in a hurtful way and try to say it in a positive way or not at all. Etc, etc" You'd essentially be raising awareness and asking for help self censoring.
But in your case, I don't think that's the way to go. You're clearly burned out and need a break (and likely new players). So, instead, I'd advise you simply say that running the different campaigns is a lot of work (because it is) and you need a break. If your players push you on how long a break, just deflect with the truth: Tell them you're burned out and you don't know.
If/when you've taken some time away from the game and are itching to come back, be very careful and selective about who you start a new campaign with. You obviously want easy going players but you also want to make sure there isn't an opportunity for any old players that you didn't invite to learn about the game from the new players.