Sophie,
I think you should just sit on that email and wait. Sometimes when we aren't sure what to do, it is better to do absolutely nothing.

Here's my take on your h's behavior...he wasn't planning to reconcile in the way you thought. In his mind, if he were to move home, it would be to cut expenses and have you "mom" take care of everything. Give him the bills he gave to you to take care of and let the man take care of them. You have far more on your plate with the children, house and trying to work some yourself. He's the one that went out there and screwed up big time in all areas of his life. When the kitchen gets far too hot, the man/child brings his responsibilities back to "mom" to take care of. Do not take on any more of his responsibilities. You are already parenting for two.

No, your h has a ways to go before he hits bottom. This guy hasn't been at it all that long and I suspect that there is ow in the picture. Something just doesn't "smell" right about him and his situation.

As for the divorce....make him work for it and allow him to pay for it. Again, give him back the two bills he gave you and tell him that you've got enough on your plate and point out....you've got the children all of the time and surely with him being on his own, he can manage to write a few checks. If he doesn't want to do that...suggest that he put you back on his checking account and give you full access to his account to write his checks. I bet he'll take them back w/o hesitation.

Stay the course and do not fall for any more of his pity parties. I do not feel sorry for him one bit....you didn't create this mess, therefore, you shouldn't be sweeping up his mess. Time for your child to grow up. Take care of your children, home and yourself. That's what is important right now.

Sit quietly, the answers will reveal themselves when you least expect them to.
The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.