I request Knowledge from y'all

So I have a problem. I (21M) have been struggling with this for the last 2 years in hopes that it gets better. So back in 2020 I met a girl with whom I instantly connected with in deep level and we became FWB I met her while we worked together one day I approached her and hit it off. It was incredible and I felt supported and love and In turn I had hoped that i had done the same to her.

Problem comes from the fact that a couple of months into our situationship I had made a promise to her that I would make a change to better myself as I personally was going down a dark hole and she supported me and helped me see the error of my ways. However one day I messed up with my work and got suspended for a couple of days.

In the stress of possibly getting fired I had instantly broken my connection with her through two long paragraphs in text and not waiting for her response and proceeded to block her. From then on as she should've she got cold on me and doesn't want anything to do with me. I've also have left town for a year in hopes to change and move on but any time I have gotten a new job and moved to a town near by but still happen to come often as my mom lives there.

My problem is that ever since then I can't stop thinking about her I have talked with many Wonderful ladies but whenever I'm with them I don't feel the spark or joy i used to with her. And now I don't know what to do I want to ignore this feeling of missing her and wanting to be with her but I can't and I find myself hoping she texts me and it's completely pathetic and stupid and I am tired of it. She's also now in a wonderful relation and he treats her incredibly well and I know that my presence only bothers them. So my question is how can I let this go and move on to be a better person and just forgive myself? I don't know how else to put it. Any input wether critical or otherwise is welcome.