How do you know when you are not infatuated anymore?

i have liked this girl now(Kym) for ages but to be honest she wasnt the person i thought she was. I really want to get this girl out of my head anyway i can because she is destroying my life. I think i am getiing over her slowly but i dont wanna develop feelings for her again. How can i stop myself from thinking about her. After the things she has said to me i should have no problem getting her out of my mind but i cant help the way i feel. pls help:)