Aww, sweetie. Okay, so first of all, fuck your friend. I can’t really think of a better way to say it than that, so I apologize for being vulgar. But if she knew you liked him, she should have helped to bring him to you rather than get him for herself. If she could do such a thing, then she was never your friend in the first place. She disrespected you and that is unacceptable,
I, personally, would just drop her as a friend. Over time you may forgive her and may even patch things up but right now, you don’t need someone like that in your life. You dont deserve to be hurt in such a way. If there are plans to confront her, take some time to calm down and think everything through before hand. but if you don’t plan on doing so, just cut contact with her. Move on and find some new friends who will care about you. I hope things work out and I’m sorry ou had to go through that!