Never, say die, oh wait, smoking does.
The biggest problem with stopping smoking is the excuses you give yourself to start again.
Smoking both creates stress and relieves it, you get the stress by not smoking, so it dupes you into smoking whenever you have a lower level of nicotine in your system. Thus the stress you have created is transformed into another type of stress. This is why you get smokers wanting ever increasing amounts of the drug in their system. Some manage to plateau by fooling themselves, sometimes for years, that they are going to stop, so smoke a steady amount, trying valiantly to stave off the craving for more.
You have to ask yourself what other activity, like smoking, raises your blood pressure and releases chemicals into your bloodstream. This is something you see people getting off smoking take to in a big way.
Being an EX Smoker I know all the excuses people tell themselves, its like watching a slow moving train crash, fascinating to see the slow motion, but powerless to stop it.
tbh I don't see how anyone can stop smoking by just giving them nicotine, without full support. I do believe this is some sort of hangover from the drug rehabilitation schemes and all those unregulated ones never worked, so why should this. Here take this drug for heroin and morphine addiction, methadone, oh thanks, now I get a legal high without having to pay for it, and I string the GP out for as long as I can, No money for smack, no problem I sell off my prescription to some poor sap who wants more, then I go and buy the real stuff. No support meant the addicts did not stop. Anyone with a drug addiction of any sort, needs full support. You don't see an alcoholic being given so many free shots a day of their drug to wean them off do you. Mind you that would certainly increase the alcoholic statistics if they did.
You really have to look at the reasons for stopping, then choose a treatment that is best for you.
Look at some of these.
People who are wanting to stop because they have been given incentives to stop will do so. Stop smoking or you will get fired, No smoking during working hours.
People wanting to stop smoking because of the social stigma of being an outcast. Hardened smokers, a group of friends who all smoke so go outside at the pub together or people who keep to themselves don't care.
People who want to stop, because of money. Pretty hard so will tend to eat less.
People who have to stop because of health. You have cancer, stuff it then its too late to the person who cannot breathe, but the stimulant action of the fag helps them breathe.
Write down all your excuses, and why you want/need to stop smoking. This is not the obvious ones like its better for my health. We all know its better for your health, so its a pointless exercise telling a smoker its good for them. Write down what you have tried before and why you have failed. I do mean physically write, as this fixes those reasons into your brain, far better than typing them in on a computer.
In my case I tried every single nicotine substitute and included herbal cigarettes. There are even fake cigs that are just menthol flavoured.
Look around and research each item that helps you stop. This is not a pointless exercise as it will focus your mind on the end goal.
Smoking is both psychological and physical. You need to tackle both, build up the mind and prepare it by fair means or foul then cut out the route cause.
If you really want to stop, I can point you to a few places, but they will cost you around £400 + overnight stays at a hotel, a small price when you think of how much you save in the long run. You will stop within 1 day as long as you are willing to try.