I Have Had An Itchy Throat And Cough With A

I have had an itchy throat and cough with a lot of mucus for the last 5 weeks. My chest gets congested and it is sometimes a bit difficult to get my lungs full for a good cough to get the mucus out. I need to stand or sit up to generate a good cough to get the mucus out. Drinking water seems to help loosen the mucus. I also have coughing attacks when doing physical work. This seemed to start as a cold a long time ago that came on from lack of sleep. I don't have a fever and otherwise feel good. I am 6'1" and 260 lbs. what do you think is my problem?