I would also second what Dee said. I recently stopped smoking pot (8 months ago) after being a very heavy smoker for over 20 years. I "crutched" on alcohol for awhile, before deciding to slow that down and finally quit altogether now. I understand what you are going through. I still obsess about smoking at times, especially if I smel it, or even think I do!! What I do when I think about possibly going back to smoking is remember how hard hard it was to get where I am. I "tried" to quit many, many times, with no success. I know if I were to even take a hit off a joint, all the "logical" thinking in the world wouldn't stop me from getting more.
I am also working with a theripist on some of the issues in my life that led me to my drug habbit in the first place. I've found that to be very helpful, though I went through several theripists before I found one I felt comfortable with. I also have regular appointments with my psychitrist about my depression, which is clinical in nature. It's quite possible my many years of smoking and drinking have altered the chemistry in my brain. I take several medications from my doctor that help address these issues. To some degree my pot smoking was "self medicating" for other mental issues.
You might want to check out some NA meetings. A lot of folks find attending meeting, and working the steps with a sponsor is esential to their recovery. Congrats on your 2 years, I'm looking forward to getting there!!! Welcome to SR!! Take care.