Help a friend...

dear fellow steemit. 

I am emotionally down right now and i don't even know where to start story from.

My new girlfriend goofs around with different guys and she doesn't give a damn if i wanna leave. I forgave her countless time and she gets so dependent in my forgiveness. One part of me wants to leave but the other part still believes in her despite the fact that she messed round with her randy boyfriends. I complained about her doing and she promised to change but she never did.

I know walking away is the best option for me but i really want to change her to be the woman i wanted her to be...

what do i do to change her cos i have tried all possible best?