I packed up smoking in the first years of this century. I'll admit to 40 a day at that time (it was more). The darn patches wouldn't stick. The chewing gum got stuck in my teeth. Eventually I found lozenges and packed up. My wife (who smoked as many) packed up at the same time using just mint imperials! Your Doc can help these days.
Last March I developed a lump. So I bought a pack of cigars. My brain switched back on! I've since switched to vaping - not quite as good in terms of the effect, but not bad.
Prior to chemo (this month) my consultant said "No smoking!". I told him I didn't smoke, I vaped. He indicated that is fine - doesn't have the carcinogenics that smoke does. I have put a kilo or so back on though but with the lump (and my assumption as to what it was) I haven't been as strict with my LCHF regime (lost 10 kilo over 14 months with that and I don't think I was ever hungry).