I have a similar story about being in the closet. I've hidden smoking from most of my family for 14 years. I promised my wife when we started dating I would quit. Then when we got engaged I promised I would quit. Now we are married and again I promise to quit. Each time I promised, I just found new ways to hide the smoking. This made her feel better because she thought I was quiting. At the same time I felt horrible. Like a failure because I hadn't really quit, and an a$$ because I was hiding it from her.
If anything, closet smoking is just adding to my stress level which is hurting our relationship. I want so badly to be able to tell her I haven't had a cigarette for a day... 2 days... a week... month... It won't be easy, but I'm going to really do it this time.