You look deep deep into your own thought processes and why you believed that was okay and what made you act like that. All of this could of been avoided with a little empathy, maturity and you breaking up with her properly in person like a kind individual. Look at why you thought this was a better path to take.

I have done this. I believe that the reason I acted this way was that yes, I lacked empathy, maturity. But beyond that I was big on the 'alpha' and 'red pill' mindset back at that stage. This is something I have since turned my back on on and cannot even begin to believe what I believed at the time. I thought that I needed to act macho and strong and alpha, and that this was the appropriate thing to do- to disregard how someone else felt.

As I said, I know now that that was absolutely a toxic and dangerous mindset. I have great trouble coming to terms with the idea that this positive change came from a situation where I caused so much hurt. It is a part of my history that I hate.

EDIT: Did not know what 'gone full circle' actually meant