Just my .02 worth but I think his ability to cut people off is his defense mechanism, learned as a child due to his estrangement from his father.
When people cause him pain, he removes them from his life so he doesn't have to feel the pain. It's his issue with himself more so than an issue with you.
He doesn't want to dig deep and find out what's there because it would be too painful.
That's a simplification of what may be a more complex issue but my H is very much like that.
All you can do is work on you. Whether he ever does that is very much out of your control.
Live the life you want to live, GAL, have fun, learn something new.
Me 57/H 58 M36 S 2.5yrs R 12/13
Let me give up the need to know why things happen as they do. I will never know and constant wondering is constant suffering. Caroline Myss