Smoking paralyzes the cilia, which are the tiny hairs in the sinuses and lungs which remove pollution and detritus. When you stop smoking, they work again, so it's possible you are coughing up what's been stuck in the lungs for a while, and it could be one of the causes of your respiratory distress.
Sounds like you also have a sinus infection, but as Londres70 notes, only a doctor can make a diagnosis.
Physician appointment yet?