Can't have a relationship with my twin brother

I'm still a minor so this whole situation is so hard. I'm 17. My twin brother got taken away 3 years ago because he came forward about my mom's boyfriend doing something to him. He has never done anything to me but he was removed from the house and he was arrested. Now in her boyfriend's statement. He never actually said my he didn't sexually abused or rape my brother. He said my brother is gay and would hit on him and try to sleep with him. And basically would say my brother came on to him and whenever they asked if he did it. He would decline to answer or bring it back to my brother came onto him. He was found guilty in Sept of 2019. My mom didn't want my brother after that. He lives with his foster family but still comes here every once and a while but it's always the same thing. My mom will act nice, then demand that my brother admitted it didn't happen and would bring his sexuality into it. My brother is bisexul and she will say "Oh did he? Or were you just curious?" And try to convince my brother that he some how lead him on. It happened yesterday and she did the same thing but wouldn't stop pushing and kept trying to make him think he was the one that came onto him and there was no rape. My brother had his foster mom pick him up and hugged me and said he loves me but he can't be apart of this family anymore. His Facebook is deactivated today and it seems like he even changed his number.... I'm heart broken that my brother would cut me out..

I definitely understand why... We've always come last in my mom's life. Not just to men. Her best friend constantly told me I was ugly and fat and her daughter is prettier and my mom told me to stop being sensitive. Idk why we aren't important to her.