So me and my girl have been togehter on and off for 3 years now. We broke up after the first year and split and saw other people. After that we got back together and stayed together but not bf and gf. At this point on we have lived an hour away from eachother. We promised eachother we would stay faithfully to one another. The two years went by and things were kinda sketchy but we remained together. About 2 weeks ago she told me that she lied about sleeping with her bf when we wernt together. She then told me that during the last two years she has been fooling around but not sleeping with countless guys at parties and even had one guy you could say she was seeing. She had lied to me every time I became suspicious which was alot. When she told me this she was dating someone else for acouple weeks that I new about. She then broke up with him because I told her I wanted to make thigns work. Acouple days later we started being bf and gf. One day after that her X bf went to her house and apparently made her feel like crap so she kissed him and cheated on me again. Shes slept with 3 guys now including me. I love this girl so much and all this came outa no where. I never thought she could have done somthign like this. It hurts llike crazy. When I ask her why she did it she says she doesnt know and shes dumb and she wasnt thinking. She also says since we wernt bf and gf that it wasnt cheating. It seems like theres somthing new she hasnt told me eveyrhting day. Me and her have talked about being together forever and I know she loves me and I love her. I feel like alot of this is my fault because I was kinda mean to her alot plus she says she thought I was cheating on her. I dont know what to do. My heart is crushed but I dont want to end everything we have. Please give me some advice...