dawn, Your h is rambling and actually thinking out loud. Yes, he left the marriage emotionally most likely long before the ea came on the scene. That's why it is easier for them to disconnect once the BD has taken place. What he has said is classic mlc talk and he is still confused because he's going back and forth.
I wouldn't leave. If he's that d@mn unhappy, he should be the one to leave. I would continue to GAL and try to get on w/your life as best as possible. Either your h will remain in the home and act out and be miserable or he'll leave. He may even talk about leaving each and every time something happens that he doesn't like. He may even attempt to push your buttons so that you will put him out. Whatever happens, do not leave your home. Only you will know when you've had enough and will determine when he needs to go.
Try to keep the focus on you. I know it's difficult when they are living in the home, but you'll need to look at him as just a roommate for now and not a husband.
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.