Dawn, Your son is very wise for his age. I'm glad you and your son had the conversation. Sometimes we need to hear what the children have to say about the situation and he made some very valid points.
I do hope that the conversation w/your h will open his eyes just a bit to what he's been doing and he will be more willing to communicate w/you.
You are a fighter and you are not done. Your book of life still has many chapters w/your h in them. Be patient and God will show you the way. Please do not try to rush the process because your h needs to go through the entire crisis to come out the other side a more mature, settled man.
Dawn, you are going to be just fine. There will be days of ups and downs, but they will get better. Keep the focus on you and your children and allow God to work on your h.
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.