Boyfriend jealous of best friend!? (She’s gay)

So my boyfriend broke up with me yesterday and we were together for almost 2 years. I didn’t really realize it but he was very controlling (always tried to control who my friends are, what I wear, where I can go, etc.) So 4-5 years ago this girl started working in my department and she was attracted to me. She tried to kiss me in the elevator one day. But I wasn’t attracted to her in that way and ever since then we became the best friends/like sisters. To make things even messier I used to have a thing going on with with her brother but it was an extremely short lived thing; it didn’t even last an entire month. It might seem weird now but we all look at each other like family and her family treats me like I’m their daughter.

When I started dating my boyfriend 2 years ago I told him about the things that happened in my past because I wanted to be transparent with him. But ever since I told he, all he would do is hold it over my head. Since I’m close with her and her family I do hang out with her occasionally and go over her house still. My boyfriend claimed that that’s “stupid” because why would i want to be around someone that used to like me. He also gave me an ultimatum and basically asked me to choose between him or my best friend. We ended up breaking up yesterday because I can’t take his ways anymore. But he would always try and put a guilt trip on me and tell me that I can’t go over her house and talk to her etc. And oh PS to make things even worse he’s extremely homophobic, which is another thing that led to our break up because I support gay rights. (We once at an argument because he asked me what I would do if we had a son and he came out to us and I said that I wouldn’t care, I would just want my child to be happy, it doesn’t matter if they’re gay or not. He flipped)