Why is this so? Need more perspective.?

Why is it that I feel this way...so, I do not want to jump into a rebound relationship or with someone new right now after my divorce this past June 2010. However, my ex already is in another relationship as of 4 months ago and it sort of bothers me. We have a child together who is only 18 months old. I just feel like he never gave himself time to heal when in October 2010 he was still saying how much he loved me. Did I tell you the reason I divorced was because I feel he had narcissistic traits. YEs, I added to things and the demise of our marriage, but I am the only who ultimately left. I remember him tellin me it would take a couple of years to get over the divorce and separation of our family, but now I see it is just talk. I think the other reason it bothers me is because the girl he is dating, I went to highschool with. So, I know her. Its wierd. We were never friends, but I remember her definitely. I guess I sit back, I know its destructive, and wonder if he is going to treat her better. I say this because if you do not stand up to him and give him his way, then he is easy going;however, that makes it unfair because he gets his way the whole time and never learns to compromise like relationships need. With this woman, she doesn't have a backbone, so I am wondering will he treat her better. I am outspoken and don't believe in being disrespected or verbally abused. So, we had a lot of arguments and problems...It sort of bothers me and I need help putting this in perspective.