I think you are in for a very difficult challenge. Living under the same roof and knowing he's in an A is going to take a big toll on you. If you cannot control your emotions (and actions)while he's living apart from you...how do you think you'll be stronger now?
Not trying to dash your hopes, but being realistic. He's made it very clear what his reasons are for moving back. If you do not have some plan in mind, you will be setting yourself up for more hurt. Are you prepared for that?
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!
