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.
That's What Augury Is For!
You were totally in line. That's a perfectly valid use of the spell, and an equally reasonable thing for your character to do.
Ditch the Divinations
If you insist on playing with this DM, you're taking the right steps. If the DM hasn't banned yet he hates divination spells, don't prepare them, and, instead, scribe such spells onto scrolls (or buy them, if that's an option), therefore reassuring the DM that they aren't for making the plot disappear but advance. Then stick to your word, whipping out the scroll of commune when everyone at the table--including the DM--understands you're otherwise out of options.
Also, if he doesn't immediately ban it, see if one of your character's magic items can be a phylactery of faithfulness (DMG 264) (1,000 gp; 0 lbs.). It takes a lot of the guesswork out of being a cleric.
Best Answer
There's a common phrase: "Vote with your feet." She's entrenched and defensive, to the point that she is vindictively killing PCs to punish players. That is never acceptable, and a very strong sign that this is beyond fixing without breaking it a bit more and starting over. You can talk to her outside the game, and that might help and is always worth trying first, but you've tried and at this point more words are unlikely to get through.
Your instinct to leave to avoid more strife, and continued unhappiness in a pastime that is supposed to be fulfilling, is right. You always have to be willing and ready to walk, else you're a willingly-captive audience. Words are hollow if you're going to stay no matter what she does. If you're going to stay, she doesn't need to change, right?
Leaving doesn't need to be hard for you or unpleasant for her
Be ready to walk, but don't try to use the idea of leaving to convince her to change, since threats aren't going to bring a defensive person out of their emotional bomb shelter. If there is no change, and it sounds like there won't be, walk.
When you leave the game, communicate clearly and without venom that this game isn't for you and that you won't be participating anymore. You don't need to justify or explain (which will just invite argument), just inform that you're not going to play. If she tries to argue with you, don't try to convince her (her permission isn't needed!), just respond by gently repeating that the game isn't for you and you won't be playing anymore, then remove yourself physically from the conversation.
You can use this calm repetition again later if she seeks you out to try to start an argument. Feel free to talk with her otherwise; she's your friend, after all. If she wants to talk about the game and you feel like it's an honest attempt to communicate, feel free to. If it becomes an argument, of it becomes an attempt to convince you to stay/return without actually changing anything, the best you can do is express your preference to not talk about that:
You can repeat that as necessary when the conversation is going in unproductive directions. Also feel free to back it up with "You're my friend, but I don't want to have this conversation now" calm repetition+leaving response.
Leaving is the best thing that could happen to her as GM
She does need your help, and leaving is probably the biggest help you can give her. She can't continue like this if she ever wants to GM again. She needs to stop if she doesn't want to ruin friendships. You're doing her a favour by leaving, because leaving works.
Why does walking work? Actions speak louder than words and don't invite argument. She can't fight a person who isn't there and make them "stop being absent!" by flexing her GM muscles. You can't fight an absence, and absences don't provoke the fight/flight reflex that arguments do, but absence is very loud. And if she's not fighting, she has a chance of hearing the message sitting in that empty chair.
Walking also discharges any responsibility you might feel for the other players: you've broken the illusion that the gathering is socially OK, and shown them a way out. You've also shown the GM that the remaining players have a way out, and maybe they can now get through to her with words. But regardless, they're their own people and responsible for their own happiness and choices, so leaving also discharges your perceived responsibility: by trusting them to use their own words/actions to take care of their own needs.