I smoked for 2 years and then chewed for two years. Started smoking my last year of high school, then switched too chewing because I was out of shape, fat and couldn't breathe. I quit chewing 2 weeks ago cold turkey. There never really is a good time to quit any thing, after all it is quitting. But, what I did realize is if you can control yourself more, control you surroundings and stress. Quitting is a breeze, pay attention to things that matter more during work that you missed out on while you were smoking.
I am 23 and manage 14 guys and maintain 9 various excavators and loaders. My job is extremely stressful given that scrap metal industries just aren't easy. College wasn't all that easy for me neither, trust me I get the whole stress thing for sure. Not gonna lie I still like my beer alot. But got that down to 2 days a week.
I say give your cigs to someone, walk to a store, buy lots of gum and start fresh.