Addicted To Smoking Marijuana, Get Compressing Pain On Breathing, Frequent Coughing, Weight Loss. Remedy?

Hi i am a 19 year old male, i weigh approx. 140 lbs. and am 5 10. not sure what that has to do with anything but figures it is background info. I have smoked marijuana excessively for the last 4 years. most likely just paranoid at the moment, but i have developed a sort of compressing pain when i breathe. every time i take a deep breath i feel a dull pain. it has been getting to the point where breathing small breaths are becoming a little painful. i have cough which isn t that bad but i do cough every now and then, and when i am laying down i tend to cough more. my mom has noticed that i have been looking thinner i do not have a scale to measure my current weight but the last time i checked i was 140lbs. i do have nasal allergies that get sort of bad during these seasons. my nose is runny and there is yellow mucus when i blow it, not all the time but occasionally when there is a large build up. im sure i probably just hav a mild cold and its getting the best of me, but i wanted to be safe and see what you professionals had to offer for advice. thank you very much, anonymus