You already know stopping smoking is hard or else you would have quit long ago. Many ex-smokers say it was one of the hardest things they ever did but the reality is they did stop. There are more people that have stopped smoking than who are currently smoking in the U.S.
You are most likely physically addicted to nicotine as well as psychologically addicted to smoking and both will need to be dealt with. The physical withdrawals are short-term while the psychological are a bit more challenging.
While nicotine makes you feel calm, satisfied, and alert it also is a crutch to deal with stress, boredom, anger, and anxiety. Many even use smoking as a reward for a job well done.
The more you smoke the more addicted you are to nicotine. In order to feel the same affect you will need to smoke more and more. There is a reason there are 20 cigarettes in a pack and why many people smoke a pack a day. It is going to take time, effort and dedication to break your smoking addiction. You may not quite feel like yourself after stopping smoking but you will soon feel good again.