Its all psycological! I quit my 14 year 18 a day habit over 7 weeks ago. My brain knows this is the last time I will be quitting, I have gone through hell and back, I had panic attacks for weeks, but after researching them I learned to not fear them so they dwindled away. I have a swollen face and neck due to my body detoxing, had a sore throat for 6 weeks, have had ringing in the ears and blocked ears since I stopped (doc says its fluid built up in middle ear) have had hayfever (immune system is busy and low) my asthma is really bad (but would of been worse if I had been smoking!) but is improving day-by-day and quickly. upside is I lost a few pounds, have eaten less (use to over eat, feel sick then smoke to feel better now I don't like feeling sick! hence less food! haha). My point was that the breathing difficulties are due to your lungs repairing, the tar in cigerettes coats and smothers the cillia in your lungs (cillia traps pollutants and debris and rids it from your lungs) and some chemicals in cigrettes actually numb your throat and lungs so you can breathe smoke in without feeling the burning sensation you should get when fumes pass these areas!!!! scary or what?! so now your lungs are going into overdrive trying to repair themselves and everything irritates them (others smoking, car fumes and my dog's fur has just started to effect me, I walked in a carnival behind a car and coughed up black soot and plhem the next day. Had I have been a smoker my body would of struggled to get rid of that!) I would go and see your doctor and discuss everything. Another thing is, when you start smoking again does the problem go away? If so (like it did with me) some of the problem with breathing could be due to anxiety (look it up, causes all sorts of symptoms) I've noticed my chest gets tight when I get stressed/anxious and my asthma gets worse, but the anxiety is going too, slowly, I use to smoke when I was stressed/anxious so its only understandable that I felt this way when I quit. Please keep up the quit, you will feel better soon, my doc said I could be like this for up to a year (I am in it for the long haul! haha) and my lungs will recover to that of a non-smoker in 2-5years (pretty good considering how long and how much I smoked!). I suggest you go to this site and read all you can, what other people have been through, it really helped me feel normal there is not enough info out there telling you this will happen when you stop. But it's gotta be better then getting lung cancer or something. Good luck