Hi Ali--you're doing great: keeping your relationship as only a PART of your life, getting on with your work, and not getting caught up in his issues. That shows such growth on your part!
He will talk to you. But it really does take 18-24 months before they're actually able to process that they hurt you. I found with my H (and read that this is what the LBS has to go through) that I could bring up things that bothered me before that point, but he couldn't really deal with them. Either he'd give me a defensive answer that I REALLY didn't want to hear (and which would differ drastically from his more clear-headed insight into that issue 18 months later), or he would withdraw. In fact, for a while if he saw me upset about anything, he'd guility assume it was about him and withdraw. It took a long time for him to be ABLE to discuss painful issues in a mature manner. But, once he got there, he couldn't stop himself, and had to keep apologizing for hurting me. Finally, he got to the point where he said he could forgive himself and let it go.
So, give yourself time, and continue getting on with your life till he's ready!