Why do exes try and hurt you, when they left you?

ok well if you read my other stories you would know the whole deal, but essentially my long distance gf found someone else while we were on a break. just as i was trying to move on she has been on a rampage and been really mean all of which i didnt respond to. she claimed she was preganant and had an abortion (she told me this when she thought i was hooking up with another girl) so i'm not sure if its true, because she never was trying to tell me while i ignored her. all she did was say really mean spiteful things. like she left me so why bring this out anymore? i was a good boyfriend i think, so why is she doing this to me? like im not a bad guy. it hurts to know that just a few months ago we were saying that we wanted to get married and all that. and now were at this level. my friends think shes doing this because she feels bad for what shes done and knows she lost a good guy and guy she still is in love with. she used to tell me that this guy is exactly like me, so my friends thinks hes just a rebound and shes starting tor realize that. and that this is just her way of making herself feel better, by making me out to be an ******* in her mind. please i need some advice, i want the hurting to stop but i dont want to do it through cutting her out. i want to make some kind of friendship. i think i should just leave it and wait for the anger to go away, then maybe itll be better. help?