The reason why your stress is so high on the days you don't smoke is because you smoke so much. You're so used to having the weed there to calm you down that on the days you don't have it, you stress out, ya know? Happened to me alllll the time before I cut down. One of the "withdrawal" symptoms of marijuana is loss of appetite for a while, so it could just be that. I don't know about the nauseous thing or the cigarette thing, as I don't smoke, sowwy.