Am I really the bad one here?

I was in an on & off relationship with the father of my child for 4 years, our relationship was extremely toxic we got to the point where there was no respect & we were basically FWB. I loved him a lot & now that I look back I know he stopped loving me soon after I had my son.

I met my boyfriend in 2019 I was still messing around with my ex but broke up with him soon after meeting my boyfriend my ex freaked and to this day he tells me that I broke him & that I’ll get my karma. I don’t understand how I was the bad one for leaving when he was out there cheating & basically living the single life while I was at home heartbroken crying myself to sleep. We weren’t happy anymore what we had was more of an attachment that I couldn’t let go of.