Well speaking from experience. Don't ask him what he wants. Do something really special for him. Something he can grab a hold of and think of you. Something really good that has worked before is a really cute picture of you two and put it in a frame. The frame can say something really cute on it or it can just be a regular frame. Thats a really good one. I'm sure he'll love something like that
I would say get a feel of what he really needs right now...even if it's the smallest thing get it! Because by the end of the day he'll feel so happy about you taking notice of the small things in his life...good luck!
I got mine a new wallet and put a gift card to his favorite place in it.and I also painted him something. So why not see if you can make something for him too. Like the card. Instead of buying one make your own. :)