Do i have chronic bronchitis?

Ive been a smoker on and off for the ped 7 years. I quit about a year ago, but started again after 6 months. As of lately, ive gone up to 2 packs a day. Ive been experiencing an extremely hard cough, with light yellow mucus and i'm constantly short of breath with chest tightness. I find lately that I cant walk across campus carrying a 20 pound backpack without needing to stop for fear of ping out. If i have chronic bronchitis what can i do to help/stop it. How long does it last? Ive have these symptoms for about a week now and since then have decided to quit smoking. Will I get better, or is the damage done? Ive been taking OTC, expectorants, mucinex, ect., but they dont seem to help that much. Is there anything I can do to get better?