Give it thought my dear, as taking care of his son properly is more important than his bills and such for sure and would you even be in this position had he talked with you in the first place? He screwed up, why should your son be put on hold because he chose to act in the way he did. He doesn't deserve to be put as a higher priority than you and your son at this time in my book.
I hope false hope of getting back together doesn't cloud your judgement, or make you go along with his program any longer, since it didn't work for you and your son in the first place. Why continue with it?
Give it thought and tell your heart to shut up on this for a while. His well being IS NOT your priority right now.