Boyfriend's friends hate me

I want to fix this SO bad, Im devastated and I DONT know what to do anymore. People: My boyfriend, Bill. My boyfriend's roommate and ex-"best friend"s boyfriend, Bob. My ex-"best friend", Sally. My boyfriend's, boyfriend's roommate's and ex-bestfriend's friends, Jen and Harry. Problem: I have a hard time defending and standing up for myself, and one day i stood up against my so called "best friend". I thought she was way too bossy, controlling, selfish, and sarcastic. And one day i felt like being brave and told her how i felt through text (BIG MISTAKE). So now, Sally hates me which makes it hard for Bob, Jen and Harry to approve of me whenever i'm at my boyfriend's apartment. I've tried to be nice to everybody in order lighten up the mood or even make them see that im waving a white flag up, i want there to be peace in the apartment but it feels like Sally put everybody under her spell to disapprove of me. My boyfriend misses his friends, and today at the apartment when they all left they didn't even say goodbye to Bill. I understand they don't like me, but why act like they're not good friends of Bill's anymore? I don't want to do or say anything, because i don't want to harm the fact that Bob and Bill share an apartment and if something goes wrong he will have to move back to he's parents. What should I do? What should I think? Is this really all my fault? I wish i never told her how i felt about her, but sometimes it's tiring keeping my thoughts to myself and being a "good girl". I really appreciate it if you can help, thank you so much.