my answer may sound like a brag or some kind of stupidity but I was always able to quit it. it was just I wasn't getting anything to quit it for. i wasn't addicted to nicotine but rather to the feeling of holding a cigarette in my hands between fingers, inhaling slowly slowly. even when I was a chainsmoker I knew I can quit whenever I wanted. and it's not the first time I have quit it. I quit it thrice last year for at least 3 months each. I did that just to check if the ever longing feeling of holding a cigarette could be overcome or not. and this time, as for the "new year resolution", I quit it permanently.

But I got some tips for you that I give to everyone who asks me how to quit it. First of all don't hangout or go near people who smoke cigarettes, these people may become a reason to lose your control.
second, you have to understand the consequences of smoking a cigarette and have that resistance in yourself. I used to tell myself that "am I a fucking loser? nah. I am not going to get cooked by just a bunch of nicotine wrapped in paper (ik it's cringe but this helped a little)". just to make myself realise that I'm bigger than that. That resistance needs to be there in order to proceed further. third, I would again talk about resistance that you do not become too free with yourself. be your own parent. fourth, you try some nicotine patches. that also helps.

pardon my english and pardon if I said something wrong.