I treated her badly, but i need her back?

Basically i met this girl last year and i have to say she was beautiful! anyways we got to know each other till the point where we were going to be official however along the way came my ex and i chose my ex over this girl, for months we didn't speak and to be honest i missed her, eventually she texted me and we started to speak again, me and my ex split up and we were going to try again to make things work however i met another girl and i fell for her, so i chose the new girl over her again. Yes i sound stupid :/ the two of us argued and she told me she didn't want anything to do with me anymore and we left it at that but i can honestly say i loved the girl even though i was with my girlfriend, she was there for me when no one else was, she always chose and put me first :/ and now me and my girlfriend are no longer together and this time i was going to make things work with this girl, she went on holiday and when she came back i told her that i wanted to be with her and no one else yet this time she said she didn't want me back, because of all the times ive hurt her, I need this girl in my life cos im nothing without her :/