Idk what I’m feeling

Long story short, I dated a guy on and off for 7 years. Ended up getting engaged in 2016. Called off our wedding in 2018 because we weren’t ready, rescheduled for 2019, and again called it off. He worked away from home all the time, and when he was home I never felt like a priority and the sex was awful. He had anger issues, and said mean things to me, so I finally broke it off 6 months ago. I’m now with a guy who treats me amazing, but I can’t help to miss my ex. We talk on and off but I don’t know why I’m missing him so much, our relationship wasn’t healthy and I know that. But I find myself wondering what life would’ve been like if we would’ve gotten married. It kills me 😩