It's is nice to hear that you want to quit smoking.
There are several methods but you need to have strongly adhere to the process you choose.You try the following process and for your own sake do not fail this time
1.Plan a date to quit smoking.(Take one week, but you know you are going to quit smoke on that day)
2.From today you cut down the number of Cigarette i.e. amount of nicotine intake.
3.In this week cut down it to just 1 Cigarette/day.
4.Start drinking lemon juice , it reduces the desire for nicotine.
5.Keep yourself busy, play games, cook, try new projects.
6.Join a Gym session.(This will really help you).
7.Stay away from smoking environment.
8.Make yourself stronger daily, take deep breaths to understand yourself.
9.Do not keep telling others that you are quitting.
10.Once you reach the planned date, STOP.
11.In between you may feel like smoking, buy a nicotine patch if you feel like so.Swing gum and chocolates are also helpful.
12.Once your body gains its past stage you will never want to smoke again.
a) Because you will to enter a new happy phase of life.
b) Your lungs will start heal itself.
c) Your chest will not ache.
Be strong.It will not only help to quit, but also improve your will-power thus making you a confident person.
We are waiting to welcome you in a beautiful Healthy Life.
Furthermore, if you feel pain in chest take deep breath and cough.Do it for 3-4 times, pain will be gone.
Note: I am not a doctor.If you do not like the ideas, consult a Doctor.