Search Results: forgiven for a mistake

I was a toxic friend to this girl. Even after forgiving me countless time I make the same mistakes. She's had enough and when I confessed she said it's better if we stayed friends. Did she forgive me all these times because she liked me or is it just because she is nice? Should I cut myself from her life or show her that I'm trying to be a better person?

We're madly in love with each other, we're a perfect match, however there's one problem.

Like any healthy couple, we fight sometimes, over dumb or serious things, we start off angry and upset but end up calmly arguing and discussing until we realize who was wrong (she's always ready to admit her mistake, so that isn't an issue, same for me).
When she fucks up and realizes she was in the wrong, she apologizes so much for hurting me, she cries and promises she'd become a better girlfriend (which she always does), and right when she says that I feel so bad and hold her tight telling her it's okay, because I know her apology and feelings are genuine.
BUT whenever I'm the one in the wrong and I apologize and promise to do better, she gives me a cold shoulder for a couple of days, thinks I'm a terrible person and hates me, and if it gets any worse we almost have a small breakup which sometimes gets me really worried cuz we might have actually broken up and I lost her, I always have that fear.
Then I gotta build up her trust and respect for me all over again which is really exhausting and time-consuming, while she doesn't have to do any of that.

So what do I do here? I think it's so unfair and I don't know how to appraoch her with it cuz she'd think I'm being manipulative, her forgiving me easily might prompt me to do worse things behind her back because she'll forgive me anyway, that's what she thinks.

I don't wanna toughen up when she makes a mistake, I don't wanna hurt her like she hurts me when I mess up, I'd hate to see her like that.

What do you think?