If I was a better partner, would he have moved on from me so fast?

It’s been almost a year (10 months) since my relationship ended and I’ve been working on coming to terms that it ended. There has been lots of highs and lows plus emotions ranging from feeling relieved to feeling sad/weighted down the next day.

For context - I was in a relationship for almost 2 years in college that started during my junior year. My ex and I were one year apart (he was a grade below me).

Overall, it was a very tumultuous relationship full of explosive fights (on my end), tons of communication issues, and overall we were not compatible. It also didn’t help that he was an avoidant and I was anxiously attached to him. Last summer in June, he told me he checked out of the relationship and that we should break up. As the anxiously attached person I am and since this was my first ever relationship, I begged him to that we can “take a break” and sort things out instead to which he reluctantly accepted. Even though we should have broken up, we hung onto the relationship until we officially broke up in September of last year bc of LDR and burnout.

For about 7-8 months and 5 months of NC, I still yearned for the relationship and reconciliation. I met up with him early in June of this year where we caught up and I realized I was no longer attracted to him. However, it still kind of hurt me when I found out he developed feelings for someone else about two months and is talking to said person before I met up officially in person. I also took full accountability for what I did and we forgave each other before I left the trip.

A part of me is struggling with the fact that I felt like he moved on from quickly. Like a year ago from now, we were still together and doing things together. It doesn’t sting as much anymore, but a huge part of me believed that if we had a non-toxic relationship where we barely fought and I communicated/regulated my emotions better then maybe he wouldn’t have developed feelings for someone else?

Would he still have developed feelings for someone else given the hypothetical scenario that we had a stress free and healthy relationship? If I was a better girlfriend, would he have remained single?

I have moved on from in the sense that I don’t yearn to reconcile with him. But a huge part of me feels like I was such an awful girlfriend that he simply developed feelings for someone else who is “better” bc I was so shitty. Would anything have changed?

I know I can’t reminisce too much about it. It’s something I am really struggling with right now but I am trying to move on.

Currently, there’s been lots of highs and lows with my journey. Going forward, if I ever get into a relationship, I am definitely working on my attachment issues on my part and also end a relationship early if I find out the person is an avoidant 🤷🏻‍♀️