How to move on from 1st love?

I met my 1st love at the age of 17 (2016). There was love bombing from the start, but I wasn’t used to the attention like that and I liked how I felt around him. There were several red flags that I ignored because I didn’t want to lose him or the feeling I felt when around him. I lost my virginity to him. He always told me that he would marry me one day and I believed it as well. We ended up moving in together shortly after graduating and I became pregnant with our son. Things became even more toxic. I gathered the courage to move out in 2020. He no longer believed in marriage and went from wanting 3 children to wanting none after we had our son. He went as far as getting vasectomy. Since then, we still haven’t been able to let go of each other and have been off and on. The sex is great and I know I’ll miss being intimate with him. We are currently trying to work things out again. He says things are different this time and says he regrets how he was before and sees things more clearly now because he never felt happy with other people. But after all the hurtful things, I’ve noticed that I have become extremely anxious when In a relationship with him, my self esteem is awful, and my mind is constantly foggy. During our off time, I did pursue a relationship with a great man who randomly got me flowers and provided reassurance on his own. It felt calm and I wasn’t used to that, but I couldn’t let go of my son’s father and the sex with the other man wasn’t good like with my son’s father. I hate that I hurt a great man when I thought I was ready to move on. Does it get easier to move on and to be able to find a good man again? I love my son’s father, but I feel like being with him is bad for my health. How do I get out of this toxic cycle? Will I ever be able to love someone else the way I do him? Please be kind…