I am so sorry to hear about your son. That is so sad, I think if I was in your position it would really tear me up inside. I think you are VERY strong to tell your son what is going on the way you did instead of letting him think that it meant his dad was coming home right now instead of just coming over for the day.
I think the conversation you had with your H was fine. You weren't being manipulative or pushy or pressuring, you were just saying, our kids are having problems and I want to talk about it with you. The only thing I would do differently, and maybe you already did this, is to only bring up that kind of topic after giving yourself a time-out and time to cool down and a waiting period to decide whether or not to bring it up, instead of making a decision based on emotions. You know what I'm sayin?
As for H's sad, sad voice, he could be sad-sad because -he is still confused -he knows he is being a jerk -he wants to be there with you but he "cannot" because he is still working through his stuff, or hasn't started yet -it hurts him that his son is hurting so bad and he wants to be there for you but he can't until he has healed himself -etc -etc -etc
You are a STRONG LADY Kalni. ((KALNI)) I am giving you some STRONG hugs. Hug the computer monitor!!