I've never smoked, so I'm not much help on the how-to-give-up stuff.
I can post a dire warning, though.
Elsewhere (astronomy forum), one of the most active, helpful, popular (and funny) forummers, posted late last year that he'd had a bit of bad news. He, a lifelong smoker in his late 40s, had been
ordered to give up, a year or two previous, with good reason. Now, he'd had a letter from his consultant vascular surgeon telling him that he had a complete occlusion of all the arteries in his lower leg and the prospects were dire. He actually published his letter in facsimile on the forum, as a warning to others.
Early this year they decided that his leg was past saving and he had it amputated. He spent three months in hospital.
Early in June he was fitted with an artificial leg and was thrilled to be able to get about again with no more than a stick, to move into a bungalow, to re-start his hobby which was running a sort of used astronomy kit exchange. All through his illness he continued to post on the forum and his optimism and cheery disposition was a pleasure to read. I never met him but, like all of us, counted him a friend. He was a passionate Wales supporter.
It wasn't enough.
On 13th June he collapsed and died of a pulmonary embolism, almost certainly smoking-related. His loss was a tremendous blow to the forum, felt keenly by many fellow-astronomers.
Please,
please, don't let this happen to anyone on this forum, ever! Or any other!
Enough. I felt, I really needed to post this, get it off my chest.