I think the best solution is therapy too, but if you're not willing to try that, maybe writing would help. IS this bringing up old abandonment stuff? Have you asked yourself why you can't forgive him even though he's made a change in who he is? It would probably be best to try to focus on you and why you're dealing with it or not dealing with it the way you are. I don't think it's about him anymore, but about how you're reacting to it. If you're having trouble trusting each other, it doesn't sound like it's something you two can work on together with out outside help. Good luck.