I smoked 20+ a day for 40 years (actually for 47 years, I had my first at age 11
and I'm now 58) and gave up pretty much overnight on the 9th of November 2021. It was far easier than I thought.
Firstly be aware that nicotine isn't addictive. Yes, you think it is because the it's in the interest of tobacco, pharmaceutical companies and tax collection governments departments to perpetuate that idea.
True addiction means that the substance you are ingesting replaces and takes over something that your body needs, so stopping it triggers a physical response. There's nothing in tobacco that your body actually needs, otherwise you'd get up 5 times a night to get a 'hit'.
Yes, you got (get) a dopamine hit when you first smoked because your brain equated it to social inclusion, or stress relief or boredom or whatever caused you to start. Most people started smoking - like me - at an age when health and cost weren't even a consideration but being cool and part of the gang were paramount.
First you need to stop thinking that you're 'giving up' - that implies losing something that's important to you (like removing an unwanted toy from a child, all of a sudden it's the best thing ever!). Instead think of it as casting off something that's rather stupid, immature and weak. Do you really want to be someone who's associated with those words?
Secondly, keep a smoking diary. Write down the time of every cigarette and why you are smoking it - habit, stress, boredom, enjoyment or something else? I bet you anything any 90% are habit. So they are the first and easiest to go.
I stopped smoking because I'm training as an interactive hypnotist so wanted to a A/make sure that it works and B/have some credibility so not sure how I can describe the next step without self promotion but basically you need to convince your subconscious that smoking is no longer a good idea and that you don't need it. The first 3 days are weird and not particularly easy but after that it's only weird!