Have you read the Detachment thread? If not, you should. It may help you figure out what you need to do in the detachment arena.
Also, it's hard because we still see the person that we loved and married, but deep down, that person has changed into the mirror image (opposite) of who we knew and loved. It continues to hurt because he's still beating his own drum and keeping you on the merry-go-round. You have to figure out a way to get off that ride, i.e., even if it is a little day by day.
Leave him to his crisis. Stop attempting to take the wheel back from God. God will drive the bus if you will just drop that rope and have faith in the process.
Keep the focus on you! Focus on what you can control and fix for 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.