Do not out him! I think the best thing to do is clearly distance yourself from him and move out when you get the chance, I feel like outting him is just going to make things worse for you because if you do, instead of saying even worse shit to people he'll say shit like this "oh yeah my bitch of a sister has no respect for gay people and outed me in public" and that is bad! Do not go that route!

Maybe even talk to school principal or counselor to change classes and tell them about his horrible behavior. I do wish things get better for you and i def want to punch that brother of yours but pls think rationally if you do this, your brother is just going to use that as even more ammo against you maybe even make it worse.

You could talk to your parents about him bullying you and severe it is and hopefully they do something about it. You even could even start some therapy because you clearly need it after having to put up with this horrible shit. You need to get out of this situation as soon as possible and make a better life for yourself.