Well, you clearly aren't long past this if you still have so many feelings about it. And to be clear, that is okay. You don't have to feel shame that you have not resolved this. Don't let other people tell you what is and is not okay to feel.
I think you have to decide what is most important to you. Can you actually set your feelings aside and help make sure your friend has a good bachelor party? If not, you may need to skip. Another option is to pull this guy aside at the beginning of the party and say “hey. I still have a lot of anger at you. I want to make sure our friend has a great bachelor party and in order to do that, I need you to give me space. Can we keep our interaction at a minimum?”
This is what I think too
Well, you clearly aren't long past this if you still have so many feelings about it. And to be clear, that is okay. You don't have to feel shame that you have not resolved this. Don't let other people tell you what is and is not okay to feel.
I think you have to decide what is most important to you. Can you actually set your feelings aside and help make sure your friend has a good bachelor party? If not, you may need to skip. Another option is to pull this guy aside at the beginning of the party and say “hey. I still have a lot of anger at you. I want to make sure our friend has a great bachelor party and in order to do that, I need you to give me space. Can we keep our interaction at a minimum?”