Am I a bitch for not wanting to go to her birthday party?

So my friend and I have had ups and downs recently. A lot of the time I am doing whatever she wants and sucking it up to make her happy which has been draining me. Her birthday is coming up and she’s planned pres at hers and then town. There is quite a few ppl invited. She’s invited me and my bf who she hates, a few girls and a few boys. She knows I had traumatic experiences clubbing with guys so I said I don’t feel comfortable drinking with other guys idk without my bf with me. She’s made it very clear she hates my bf and he doesn’t want to go unless I want to. But I don’t want to, I hate clubbing now and I’m a year older than her. I don’t like drinking around ppl I’m not familiar with and mostly I just don’t want to be her friend anymore because if she wants to do something I have to aswell and no reason I give her is good enough and she cracks it with me. I know it’s her birthday and I should celebrate her day and it’s just one night but at this point I’m such of sucking it up. What should I tell her? Am I the bitch?