What can I do to get her back?

In december i told this girl that she would be the next girl that i date. but a couple weeks later i dated another girl. then two months afterward i started dating another. she acted cool with it until recently. i ignored her for a couple days then wrote her and told her that i was a lot happier when i wasnt talking to her. i didnt talk to her for like another week and then i wrote her again yesterday cuz i was upset. she asked y i was talking to her if im happier without her. i said "fine i wont. i thought ud actually CARE about me and my problems tho. but u just made everything worse." then i blocked her number and unblocked it today. and she wrote something like this. she said that shes given me too many chances. first i "put her in line" and lied when i said i was going to date her. she also said that if i really loved her (i told her i love her and i still do) that i woulda dated her and not went off on her yesterday (i cussed a little at her) and that shes not ganna put up with me anymore. she said that i shouldnt treat a girl like that, and that the fact that i said i didnt to anything made it worse. (i said i didnt do anything wrong to her.) and then she said she really liked me but its not a great idea to talk to eachother anymore... so what can i do to get her back what can i do and say to her to get her to like me again thanks