Hi Jessica, sorry to hear of your relationship problems. As you and others have said, the death of the close family member has made him change his outlook on life and has perhaps made him realise his own mortality. He's probably feeling he doesn't want to waste what time he has.
I do think he is treating you insensitively though. It's not your fault he has these feelings and I think he's being quite cruel. I'm sure you offered him support when he was going through the grieving process. Perhaps the death has affected him more than either of you realise and grievance counselling may help.
As for moving out. It seems your husband is the one with the problems, so I don't see why you should be the one to move. If he want's personal space, then perhaps he could move out, so he can sort his head out and decide what he wants, instead of keeping you dangling.