Hi Someguy!
I am glad the advice that people is giving you is working.
For what you are telling me though, she really does not deserve your concern, not even to make her unhappy. She doesn´t seem to have deep feelings neither for you nor for the rest of people she knows. The best way NOT TO HURT YOURSELF, is to move one, go out with your friends, and girls you like, but NOT thinking about her, not doing it to hurt her, because that will just make it a longer recovery and a waste of time, and also, it won´t let you to enjoy the things you currently have to the fullest. Have fun because YOU deserve it after what you are going through, and YOU want to enjoy life.
Placing YOU instead of HER in your mind might seem only a language issue, but it is not, it is the first step to take control over your emotions, and don´t let her manipulate them. As far as…why she called you a flag? If you do as I said…soon you will realize it doesn´t even matter.
Hope it helps Someguy!
Natalia