Imediate help needed, family of the girl i love.

okay, so ive been on and off with a girl for 6 years, im madly in love with her and she says she loves me too. we got together when I was 15 and she was 14. after a year things happened and her parents have banned her from seeing me & still to this day sit on that ban & will not let her see me. weve gone behind their backs on and off for the last 5 years but she is having problems with lying to her mother (her parents have split so she lives with her mother, sees her father twice a week)
Im just looking for help on how can I get the parents or maybe just the mother to forgive me? to show her im a different person and try and work things out?
I need this so badly.

What things happened?

Need more information.

Right, so we were caught having sex in her hot tub by her father when I was 16&she was 15.
She got pregnant & had an abortion when she was 15
her mother caught us having sex
me and her father have almost got into a fight several times
Her mother, Her and a girl I was going out with at the time (who I also have a child with) had massive arguments in a local pub
I cheated on her (I know im an idiot, I was 15 and stupid!)
Ive argued with the mother

I know its quite a few things, but they all happened so long ago (the one with my daughters mother happened 2 years ago) My parents originally said I wasn't to see her but they have gotten over it and welcomed her back into my home, surely there has to be a way for her to forgive me, shes only human.