I Feel Gutted And Betrayed Should I Hate My Ex Fiance For This?

I just cant stop feeling hate towards my ex fiance whom i was with for 4 years. we were due to get married last year but got cancelled because of family differences and i told her we would reschedule and get married as promised. we kept in contact after everything happened would even go out and do the things we would. but now she said she is going to marry someone else and to make it worse its a mate whom i have grown up with and see everyday. i feel betrayed and hurt its like im attending my own funeral fair enough i made a mistake and did not marry her when planned but she said she only wants to marry me after everything happened. but now she said her family is happy for her with who she is marrying as they know the family etc etc. Fair enough is she wants to get married to someone else she has every right to but to marry someone i know and brothers i know is a right low blow surely she could have said i will not marry him because he is best mates with the guy and its not fair on him, but it looks as if she is not bothered. Who’s right in this and who is wrong? i still love her soo much and she even said deep down somewhere she still loves me but yet shes prepared to go ahead and do this? do you guys think that what she is doing is acceptable at all?