Very Important: relationship with girlfriend getting broken?

My girl friend after 2 years of relation (it was very intense relation with all sort of things!!!) with me now planning to get settled (she has moved to another city since six months and we haven’t met since that time), we knew we could not marry each other but we decided that the girl and me (if required as I have planned not to marry anyone) will only go for arrange marriage although she will talk to the prospect to understand him but she will stay within limits so that she don't break the promises and not get into situation that will turn that first into love and then marriage. Now a time has come and she was presented to a guy who lives in another country with time difference of 5 hours. Now she is talking to him for almost two months. We have lots of fight over this period with me accusing her of breaking promises as she also stopped giving me time but she would talk to that guy late late nights do late nights skype with him and I found her talking to him on skype sometime even so late as 1 or 2 hour of night. And I know from the past that this girl had this tendency of getting into wrong kind of talks when she talks at night. She started that kind of talks with me and forced me too to talk such kind of things at the very start of our relation and so I always used to take a promise when time comes and she has to talk to a prospect try not to talk at night, don't get any situation like meeting at a place where no one is around as when with me the 3rd date she kissed me 5th she smooched and rest you can imagine. She justifies her talking to that guy late night saying that there is a time difference and someone has to adjust (but why not that buy?). Now my question is what you all think of this girl isn't she going away from what she promised? Because of all this fights she has ended relation with me and says I am no one to ask her question and I ask for so many explanations although at times and says I made her life hell she still shows love but when I ask anything about the guy she would start fighting. How one can justify a girl talking to a guy daily at night who is still just a prospect The reason why I feel the girl is at fault because I accepted the girl even after knowing the fact that the girl had that kind of relation with a boy and was with him for 5 years. She also forced me for that kind of relation and this is the major reason why am not marrying as I cannot do anything with any girl after doing those things with her. All such kind of wrong things were started from her side and I used to think she loves me so much that she want to do everything with me but later I came to know she had done all sort of things with her previous boy friend too. I have so many things that are against her that proves she was wrong and se forced me into wrong things and also that she promised so many things and so at times I say to her that get yourself right else I will reveal what all she has done to her parents even on this she instead of showing fear or accepting her fault would accuse me. With all these happening I have lost everything my parents have turned against me no one is a friend of me just because of this girl I avoided meeting any friend as since two years we always used to meet and if any weekend I would say that I have some work or meet a friend she would not let me leave her
Please you all suggest what I should do. I still want that our relation at least friendship could be revived but she in no mood to accept her fault and I know for sure with she in continuing those talks with that guy will never accept her faults. I have at times said I will expose her wrong relation in front of that guy and parents I know am wrong when I say this but even that doesn’t affect her. Also her father is somehow aware of my relation with her but when he came to know I said this to her he said to me I am just like an elder brother to her and should not talk such things. He kind of slapped me by saying this and the girl didn’t opposed her father at all even when we shared that kind of relation (P). Is this not too much to tolerate for me I still cannot live without her I have lost everything since six months I haven't ate out watched any movie haven’t done any shopping as I am so used to being with her wherever I go her absence haunts me as I have done all these things only with her and I come back crying. Its six months not a single night have passed that I slept for more than 3 hours. Please help.
The important point about all this she blame me for all what has happened but in past two years when we were together she used to request me to talk at nights meet me on all weekends she could not accept a no and would create a scene if I would say its not possible to meet and eventually I had to meet her. Even after so much things have happened I love her a lot I cannot leave I just want to be around her and she respecting the relation. she broke relation with her first boy friend and when she used to talk about her first relation with me she use to blame her first boy friend for it and now she breaking with me and blaming me too gives me a feeling that even in breaking her first relation she would have been more responsible. Is she not on the wrong side?