Happy belated birthday, my friend!!! I didn't know we were the same age!? Welcome to 37, I've been here since September.
Good job walking out on him with the kids. Absolutely necessary. Not because you or the boys were in danger, but because you needed to "Mommy up" and show him that he is an adult and needs to handle his problems and show patience like we all have to.
I agree, wait until there is some breathing room with finances (sorry about that, so hard!), then start talking with him. Until then though, it should be clear that he needs to treat everyone with respect.