I've not smoked for over 3 years now, having smoked for the preceding 20 plus years. It was one of the hardest addictions I've ever beaten, and as benign as nicotine may seem (given it's legality), it's an absolute pig to beat.
I used patches to wean me off the physical addiction (the easy part) but the psychological side of it is the real problem. You've really got to want to stop with some conviction if you want to break free because it'll be hard. Even now, after all this time I occasionally crave a smoke, or reach for my (now absent) tobacco tin without thinking.
On the positive side, once you're clear, the benefits are massive, from the seemingly obvious effects like no longer coughing up phlegm and being able to run a few yards without collapsing, to the joyful and surprising, like being able to blow up a balloon for the first time in my life.
To anyone reading this who's thinking about giving up. Good luck and I hope you get through it using whatever method suits you best. It'll be hard, but it'll be worth it.