I need opinions (kind of long)

The father of my child and I broke up a week ago. It was a pretty nasty ending and I moved in with my brother and his family. My other brother is also living here. But I don't think I can continue staying here anymore. Four years ago, after my mom died, I had to live with them and it was just bad. My SIL is never forthcoming. She always would lie about something bothering her and then turn around and cry about it to my brother, who would yell at me. The other day she wrote a post on fb that said "When you're back in a terrible situation with no end in sight 😢". She made it only visible to my brother and I but she obviously messed up and meant for only us not to see it. I haven't said anything about it yet but I just don't want to experience feeling like crap all over again. I have pretty bad anxiety. I've been thinking about moving back in with my ex and living like roommates for now. It seems like the lesser of two evils but I don't know.