Hi Jeannine,
Glad to hear all about the good things in your updates.
Here's a little twist on the not being there when they get home routine that may get him thinking of breaking some of his patterns. As a caretaker, I know its tough on you to get out sometimes, but what if you slipped out into the backyard as he came home or something, so he would come home and have to search an "empty" house looking for you. Maybe you could time it so it looks like you're coming back from a neighbor's when he finds you. Just offer a simple, "Oh...you're back?" like you're lost track on long he's been gone.
The feeling he gets while looking for you might be unnerving enough for him to start sharing more of where he's gonna be.
I like Shiny's term of "flashbacks" ... like a reflex. Don't react to them and it will pass. In time they will become less frequent and slowly fade away. Its a natural part to the adjustment you are making from survival mode you were in just a short time ago to the much better place you are now. Instead of jet-lag ... its DB-lag. It just takes a little time to adjust and get comfortable again.