I empathize greatly and I do admire the quality of your love for your husband. He's a blessed man indeed.
That being said, You are too close to this to be his therapist and peharps you don't quite realize it but that is what you are trying to do - FIX HIM. Only he can that - when and if he's ready.
Eerytime you approach him with your suggestions or your comments or your questions, you make him feel exposed and vulnerable so he retreats into the shell of his silence so as to feel safe.
So what do you do? Get the support that you need to help you cope with such a very complex, difficult and painfull situation. Take care of you. Only your husband can take care of him!!!
Your fellow journeyman,