I was the toxic one

I was selfish, argumentative, and codependent, and it not only ruined my relationship but ruined my friendship with a mutual friend who saw my shadow self for the first time. I don't know how I managed to not realize how unhappy I was making her until she ended it. She tried to communicate with me and I was bad at listening. It was just entirely my fault... but im still hopelessly in love with her. Every time she talks to me I think about how in love with her I am. She says she still wants to be friends and I don't understand why.

[Disclaimer - I never cheated or became violent, I was just a complete jerk towards the end. Absolutely toxic. I have since gone back to therapy, adjusted my medication, and taken full accountability and apologized to both my ex and my ex friend. My ex still wants to be friends, but ex friend has cut me off permanently.]

How do I move on from this? I blew up my own life with my complacency and now my two closest relationships are gone. I am the villain in someone else's story; i was a loved one's unhappiness. It feels like I'll be stuck in this emptiness forever and I don't know how to cope.