Should I get back with her or ger over her?

Ive dated this girl for 4 years. All of highschool and as soon as University began, she moved away. She didnt move far only 2 hours but the change in our relationship was huge. Before the move we were with one another every day for most of the day and after the move i saw her on weekends but we wouldnt talk much during the week. I started to feel differently, and i began to worry I didnt love her. I asked her if she felt different and she said she didnt. I tried to ignore it but the feeling kept comming back. I started to wonder if i should break up with her to protect her from getting hurt later on, But i knew i didnt want to break up with her and i knew i loved her. One day i tried to talk to her about it and she kept asking me questions that i didnt know the answer to. She broke up with me, and told me we would get back together. then she told me that we would be just friends and if i wanted to get back together i would have to start fresh. Now she's out partying nightly and rubbing it in my face seemingly. She knows Im unhappy, depressed and angry about it and yet she still does it. I want her back but she wont take me back until i promise her its her forever and nobody can promise that. so please tell me...WHAT DO I DO!?