Your 11yr old sounds amazing. Careful not to load too much onto him though.
In a way your situation is simple because your RAH has already checked out. His roller coaster recovery has given him some revelations, whether they be right or wrong, about your marriage. Now you're left with learning to cope with your own situation, even if it's not what you'd choose. His reply to your text could be translated as 'don't hold your breath'.
So, as others have suggested, get your legal and financial ducks in a row. You might be hoping he'll change his mind but act as if he won't. If you still have hopes for your marriage sorting out your own side of the fence and your financial short-comings can only help you.
There are big rewards in store for you by concentrating on yourself and what you need to do.