What else could I have done?

[antlers]

I do not know what your story is exactly. But I do know you feel guilty. If you did things that were horribly wrong then I understand your need for forgiving yourself. You can also examine if you did these things then what is appropriate to fix them in the future and apologies for the past. That would be just

I was mean sometimes. It wasn't because of her. It was because of me. My behavior was reflective of how I felt about myself instead of how I felt about her...but she was on the receiving end. I was a broken person. I fixed it. And I did everything within my power, after the fact, to fix the damage I'd done to her. I couldn't/she wouldn't let me/wasn't receptive to it. It took me 3 years to get to where I could finally forgive mysel, which I have. I still feel bad for having treated her like I did.
But I'm struggling to let go of a painful past, and of her...and that includes letting go of who I was in that relationship.