Sounds to me like he's really sensing the tension at home. I'm sorry there's so much going on! Personally, I would give him as much reassurance as possible but also avoid any AP at the same time. After all, he knows things are not right but he doesn't really understand what's happening either. I would spend as much one-on-one time before bed with him as you can, reading books or whatever, and then have a little talk about I'm here for you, it's time to go to sleep and I'll be here if you need me... that sort of thing. If he needs a couple pats, then ok that's not the end of the world. But you don't want to be standing there patting all night either.