I need advice on how to move on.

[Xiahou]

We've had this song and dance before actually in high school.

Maybe it's just me, but I think you have the right to be a little angry here. Don't get me wrong, you don't want to rage out and do anything stupid- but it does sound like she was using you a little and I agree that cutting contact is the best course of action.

The way I see it is that she wants to be free to have flings with other guys as she sees fit, but still wants to keep you on the back burner as a "friend" when she wants the emotional support that she won't get from her dalliances. That's a very one-sided relationship. She's getting everything she wants and you're being torn apart emotionally by it.

Maybe she isn't even consciously doing it, but I think you're being used. Cut off contact. Otherwise you'll see the same "song and dance" over and over again.

Edit: Also, to echo what others have said- find other things to occupy your time and energy.