Dreaming of my ex and I don't know what to do!

Looking for help from anyone with knowledge or experience with this problem (possibly a good listener). I broke up with a guy just under two months ago. We were together for six months and I had very strong feelings for him. We had discussed a possible future together and we had a lot of fun but there were problems. He had some emotional issues and as a result he was very paranoid, jealous, and possessive of me. At the end I started to feel like I was being emotionally abused so I left, even though it was really hard. He didn't take to it well and kept trying to contact me to beg me to take him back. I knew nothing was going to change becausewe'dbeen through a part of the same fight before and Icouldn't handle it, so I cut off all contact with him.

I know what I did was right for me and after a few weeks I started to move on mentally, my only fear is that he was so emotional because of past problems, that my leaving him will have done him serious mental harm. When I'm busy I can push that out of my mind, but if anything reminds me of him (even something as innocent as a relationship on a tv show) I start to feel that guilt and the what if's start up again in my subconscious. Then I dream about him. Sometimes it's flashbacks, sometimes it's scenarios of what might have been had I not left or I'd taken him back, and sometimes it's complete nonsense but I always wake up stressed and sad. It's gotten to the point that I'm afraid to go sleep because I don't want to deal with this. I've tried sleeping pills but it doesn't make a difference. I can't control this and it's incredibly frustrating. Does anybody know anything thatcould help this situation?