As one who goes to school in an area where a lot of people smoke (at least compared to up here in NJ) I can tell you that smoking can only be bad for your health. The people I see that smoke are outside smoking in the frigid cold and blowing rain to get their fix while I am inside, toasty and warm, and doing my work. People I know that smoke are constantly on edge and tied to their addiction, which, mind you, is pretty gross and tends to repel non-smokers.
Heck, down in Virginia I've tried basically every form of smoking tobacco there is out there, they're absolutely crazy about it, and trust me, none of them are worth a major part of your time, and cigarettes are the absolute least/worst form of smoking. In fact, I can't think of a more unhealthy way to smoke than simply inhaling it directly. At least with pipes and cigars you only take it into your mouth and actually try to avoid your breathing passageways. The first and only time I tried a cigarette, the guy handed it to me, and I puffed some smoke into my mouth and it only got about halfway down before I felt like needles had been stabbed into my lungs and I coughed something horrible and felt worse for hours after that. So yeah, I can't imagine what the stuff does to people who actually smoke it on a daily basis.
Good choice. And don't worry, I can see why you're struggling. Nicotine is one of the, if not the most addicting drug out there from what I hear. Why else would I spot my formerly healthy hallmate outside smoking one day and telling me "it's just something I started and do now" (for no reason).