How to stop thinking about it?

okay, I broke off my friendship with my friend i don't know...two weeks ago? I don't even remember. But anyway, I keep having stupid dreams about her even though I don't even think about her at all. I'm sure she doesn't think about me either, but am I just experiencing pain because of what she did to me? I don't understand. I kind of miss her , I just think about the good times but then again she treated me like dirt. How do I just get over it? I've been hanging out with other people over the summer but I just don't know...how do I get over it?