MJ - I know it's hard to let go and hope that he does what will help you both, but you really have no control over this.
The fact that he is willing to go is a great first step. It takes some folks a while to really be honest with themselves, and start dealin with the difficult stuff. Confict Avoidance can be detrimental to any relationship, and it is usually fear driven. Fear that you are going to make someone else mad, or let them down. I have this particular issue myself, but what I found was if you actually face that hard stuff head on, and talk about it, the fear disappears, and the person that you are dealing with the conflict on is usually very appreciative for your candor, and upfrontedness. He just needs practice. He needs to feel safe and not judged, and I know that is a shit sandwich for you to eat, since he has destroyed your trust. But it is true. 7 principles has some exercises in it (I think) that helped me to be less this way, but I still find myself doing it esp with the really hard stuff.