Jak, Maybe talking is too narrow of a goal, and needs to broadened to self-expression for your H. He needs to find an entry point that he would be willing to try for his own self-improvement.
Does he have any artistic inclinations or interests? Would he consider dance, painting, writing, crafts? Maybe you can find poems that reflect your situation or feelings, and he would let you read it to him.
This would change the pattern of how you communicate. Maybe it would influence him in a different way than straightforward, literal verbal talking.
He certainly needs to work on self-expression. His avoidance around this issue has created a huge intimacy gap between you two, that you are understandably growing increasingly less tolerant of. Maybe you need to approach this issue in a different way that still promotes self-expression but puts less pressure on him to talk.
You're looking for him to talk to you in a way that provides reassurance for your worries about the OP. He doesn't have the skills at this time to do so. You can look for ways to connect with him that don't involve talking, and allows him to express himself nonverbally (like dancing), or you influence him to engage in an activity that promotes self-expression, or you express how you feel to him in a manner that is different (ex. poetry).
This would change the relational patterns as you suggested needs to occur.
CL
CL 53 W 54 M 20 yrs. 03'-09' Separation + Old Patterns + GAL 10-14' Piecing
"The Master allows things to happen. She shapes events as they come."