You're dealing with a whore. You just thought you weren't which is why it hurts. She's a salsa whore which pretty much makes her a vampire.
You have mutual friends which means she can inflict further wounds on you. Be very, very careful what you do. Do not underestimate her. You could try to mind control your mutual friends against her but that is a risky proposition. You could try to make her jealous but this is very difficult to do to a salsa whore who has dick on tap. She might just start fucking your friends to make an example out of you.
Best recommendation: Ignore the situation and no I don't mean ignore her. Ignoring her is passive aggressive and she will pick up on it and boil you in a seething cauldron of hate. If you just can't help yourself, if you MUST delve into the lair of the beast then I recommend the following. When you are somewhere private tell her you thought you guys had some feelings but if you were mistaken its no big deal. You put the ball in her court like a man, right to her face. No anger, no jealousy, and no passive aggressive ignoring. Its just as simple as, I thought you had feelings for me, was I wrong?
By doing it this way you don't have to ignore her and have a friend war or any other kind of war. You look like the bigger person and there is an outside chance she will get with you. This is the best middle aged man advice I can give you when dealing with the opposite sex.