How do i stop fighting with my ex?

I actually broke up with my ex. Not once but twice. After both those times i felt like **** for doing it and couldnt help but think i made a mistake. After this second time she hasnt let me back cuz shes hurt. its been a month and a half now and im still fighting to get her back. She wants me to stop fighting with her so she can "pick up the pieces" and get back with me....she says the fighting is pushing her further away and its hard to talk to her now because i reaaaally want her back now and she wont let me back until the fighting stops and i guarantee that i wont break up with her again....what do i do? i feel so screwed and alone!!! help!!!! i cant do this anymore. I keep setting myself back by fighting.