I have been working on treating H like a house guest, as my DB coach suggested. It seems to be working and there has been a definite lightening of the mood around the house the last three or four days. H doesn't seem to get scared off quite so easily and he actually initiates conversations with me and tells me funny stories about his friends and people he works with. A week ago you could have cut the tension with a knife in my house, so this is a little leap forward. At least I am starting to eat a little better and sleep a little better.
I go about the house doing my own thing in the evenings after work and pretty much ignore him and what he is doing. If he initiates conversation I always answer back in a friendly voice.
I believe his love language is acts of service, so I have started doing little things for him here and there, like making up his bed with clean sheets, or making sure he had bread and milk and basics in the fridge when I went away last weekend. He seems to be appreciating these gestures.