Confusion

I am so confused. I dated a guy off and on for 3 years. I feel I was tricked and that he was never who he said he was. I had an off feeling from the get go. He's very arrogant and emotionally stupid....meaning he doesn't handle emotion or communicate well. When we first started seeing each other it was never supposed to be a relationship. I'd just gotten out of an 8 yr relationship with my son's dad, whom cheated numorus time, one person being a best friend of mine. He was still getting over someone he was seeing who was in a relationship but chose the other person. He'd fallen for her pretty hard and I just wanted to be there for him thru his healing, we also has great sexual chemistry. Well eventually he asked me to be his girlfriend. Not very long after he asked me I found out he had an Ashley Madison profile. I confronted him and he said he'd made it during one of our off periods but never deleted, I chose to forgive and try to move forward, I didn't consider the relationship to be a serious one until he got close to my son and asked that it be serious. Well eventually we broke up because things just didn't feel right, but tried to stay friends, as soon as I started seeing someone else he wanted to work it out. It got to a point he was saying he wanted to marry me and thought of my son as his own but he was always emotionally unavailable, so I called things off again, he said he didn't want to break up but when I asked to work on things he said I deserved better and that he couldn't be better but still wanted friendship and time with my son. In anger I said a lot of mean things and cut him out of our lives. I truly bet this is what's best because having him around is painful and my intuition tells me I was used and tricked. Friends and family agree but I am still confused on wether I am the bad guy. Please any advice would be greatly appreciated as I'm still struggling weeks after cutting off contact.