Support his decision,it takes a lot of guts to step up and make a confession of that magnitude. Try to understand his emotional inner battle with feelings he just can't over come I have a gay nephew,when he came out 10 yrs. Ago,the admission nearly gave him a nervous break down. We banded together as a family and helped him get through the transition,you are a special friend to him your support will help him move ahead. You may feel betrayed at this point,but finding out now is better than later,ultimately your re-action is your choice,THINK before you act. In the end what you do is on you!
Break up right now, a girl can compete with thousands of other girls, but never with men over a man....and hay don't try to fix him you will get to no where
You should be there for him. Don't make fun of him and don't think that it was your fault.
Just tell him that you know what he is and that it's okay , but you need to find someone else and be happy again.