How to stop these dreams I'm having about my ex boyfriend?

I was in an abusive relationship for 4 years. Every time he physically abused me, I would try to leave him. For some reason, I always caved in and went back to him. His “I’m sorry, I love you, I’ll change.” lines, I always fell for it and went back. Most of the time after he would hurt me and I left, he would go out and party and have sex with a girl. I always found out about it every time we got back together because she’d call the house upset due to the fact she knew he was back with me and she was basically just a nobody in his world. This vicious cycle with him and the other girls went on for 4 years, the bruises never taught me my lesson but when he slept with another girl while we were broken up, she got pregnant. 8 months of her pregnancy, he ignored her and never told me about her or her pregnancy. I guess her being almost at the end of her pregnancy, she pestered him on the phone and begged him to tell me, she would call all hours of the night and he never picked up her calls. I put my foot down and told him to pick up the call, I assumed he cheated on me again and I wanted to know with who and when. I guess the stress of it all, he finally cracked and told me she was pregnant. He cried and cried and said he messed up. He said he loved me, wanted me, the usual crap he’d always tell me when he would make a huge mistake in our relationship. I left him for good that time. Him lying to me for 8 months and her being pregnant just shattered my world. I had this horrible vivid pictures in my head of him and her having sex. I went on vacation for 3 weeks to get away from it all, never got the closure I needed. I just ignored him, his calls, his emails. I was too upset to even talk to him. I had nightmares of him and this girl and her pregnancy. I just wanted him out of my system. I guess that was the worst thing I could of done is going on vacation far away and not talking to him. It has been 6 years now, I dream about him a lot but not the girl that has his child anymore. Usually these dreams are of me and him being together then I find out in my dream he’s cheating on me. Or the other dream I have is when I’m trying to find him in my dream but I never can find him.

What is your opinion on the 2 dreams I have about him?
I’m assuming the dream where I’m dating him and I found out he’s cheating is just a painful memory I have in my head of what he did to me in the past?
What about the dream where I’m always trying to find him but I never can.. does this mean deep down inside I want closure?