So, he is giving you some useful (if painful) clues here. He feels trapped and cornered when you have these kinds of convos. This is why early advice is to back off from having R convos, which won't go well. Cornered people tend to push back with anger or actions - moving further away from the M and you.
So - first action is to not initiate these kinds of conversations and purely validate (and avoid them if possible) should he initiate one.
As for dark - that doesn't really sound possible in your circumstances. Dark is when you don't even respond when he contacts or talks to you. I don't think that is realistic, or would help your situation. However, you may want to work on dim. Now, dim doesn't mean cold, it means pleasant, minimal, busy with other things.
From your post, it sounds as though you want to make a dramatic change to your communications. In general, it's never a great plan to make decisions like that when your emotions are running high. I think it's best to work in more subtle ways - gentle withdrawal and dimness - having your own plans, being busy with things. Essentially, you 'back burner' him whilst you get on with your own stuff. However if he approaches you, you are pleasant - albeit brief.
Does that help at all?
T 13 M 7 Me 48 H 46 SS 15 BD 7.14 PA D final 5.16 (H filed)
We receive & we lose, and must try to achieve gratitude & embrace with whole hearts whatever of life that remains after the losses - Dubus