I am in the same position Hayfmr! My AH has been working his program for about 11 days now. I am emotionally just done with this situation and just when I was ready to walk out the door I started to see a change. It's lovely how that always seems to happen huh! I am so confused and don't know what to do, but I feel that the look from afar approach may be best also.
Personally I am going to use this time to work MY program and try to figure out what I want out of life again. I have lost site of what I want to do. My focus has been on this situation for so long it sounds good to let go and focus on ME! The way i look at it is if AH and i are separated for a month, a year or whatever it may be and we can sort through this garbage than what's a month or a year compared to a whole life together. That's really a short time amount of time when put into perspective!
I hope you will find peace with your decision!