Your well aware of flashing yellow lights right? Proceed with caution!
I wish I had the magic answer, but I don't. This sounds like a real, real, real problem. Yours is certaintly not a cut and dry case.
My only suggestion is time and patience. You have a real mine field here and only one step at a time will prevent you and your husband from having explosive situations. Don't forget ,whenever he gets to learn the truth, his world will be affected too.
Your in a better position to know your husband. You gotta know his strengths and weaknesses. Does he sense any difference in your attitude about him, the org, friends and about yourself? How normal can you remain without him suspecting anything? I certaintly don't envy your situation.
If only you could go a vacation for a month, it would be a start in getting the ball rolling. You see, after coming from a vacation you would have an excuse for being different or he will notice a change in you. The very thought of him allowing you to go vacation without him, will create a guilt trip in him. He would blame himself not you for changing or being different. (Anyways, it was just a thought. It happens only in movies.)
You have my understanding and I will be thinking of you. I wish you the best results.
Guest 77