Have you survived being miserable? So can he.
He has the CHOICE to ask to stay with a friend, but he is CHOOSING not to take it. That doesn't make it YOUR problem.
You have children, you need to be in the house. He does not.
Look at it this way. Those creeping, obsessive thoughts are not that different from what alcoholics experience when they want a drink. Most alcoholics who pick up a drink in early recovery do it to shut off that damn VOICE in their head telling them they need one, they deserve one, one won't hurt, c'mon you can start again tomorrow.
You are experiencing the SAME THING. You have the same choice anyone has--give in or don't give in.