Matilda, Maybe moving closer to the reality of a D is what he needs to realize that it's not the answer to his problems. As long as he holds onto his idea of a D, than he can create his own fictional reality in his head.
A separation is useful when the parties are ambivalent about the R and need time to sort things out. He is invested in his version of D as the antidote to his problems. Let him experience the consequences of his avoidance. I don't think there's any other way.
It sure makes for more drama than you care to have, but I don't think there's any other way at this time. Put your raincoat on and prepare to get wet.
Let's hope he backs off on the D idea.
He's not in a position of strength to be making these kinds of decisions. I believe one gets a D when they realize that the other person is no longer willing to be a partner in the M, and they've made personal changes, and have given the other person ample time to turn things around. Your H is using D as an escape.
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."