It is for this very reason, that he feels the panic and anxiety (because of something that happened in his FOO) that he erects his defensive system. He is reliving the feeling of being attacked, blamed, shamed or whatever. If his FOO was severe, then he could have the same emotions as if he were experiencing a life-threatening event. So pulling back into his shell is completely understandable.
IMO, your part in this is to NOT rescue him so he cannot run and must face his fears, but at the same time to be very compassionate and supportive. If he feels alone, then knowing that you stand by him and will not leave him may be the most comforting thing you can do. After all, the enmeshment you two have is intended to serve this very purpose, is it not?
To tell him that you are fed up and ready to throw in the towel is the WORST thing you can do. That would really be you putting up your defenses to comfort your feelings of anxiety, to which he will respond accordingly, right?
"I am who I am, why can't you just accept that"
Yep, I've heard that too, and its all a deflection. The tactic is a sort of reverse guilt thing... I respect you and accept you for who you are, so do the same for me. It casts you person in the role of trying to change and control him. Being the functional, differentiated beings we have become on this board, we immediately realize our "error" and back off. The truth is that we have only been duped.
