Well you should start thinking about giving up the habit.
Understand that you are addicted to the nicotine and the habit of smoking so it wont be easy.Do use some form of Nicotine replacement therapy for at least 6 months when you decide to quit, for me the 4mg nicorette losenge did it.
After smoking for 45 years i too was having breathing difficulties, what really gave me most of my motivation was when the price rose to over $10 a pack, i could no longer justify taking that much money away from my family so i could blow $4000 a year on smoking.
Been 2 and a half years since my last smoke and even though i get the occasional craving for a smoke i let the feeling pass as i cant afford to re-establish the habit and i really dont want to go through the hassle of quitting smoking again.
So tell your mind its over,you aint ever going to be a slave to that addiction any longer, take that monkey off your back and put him down with extreme prejudice,its ok to get mad..

good luck