Ok, first off, your body is telling you that smoking is bad. Have you tried to quit? There are so many free programs out there to help you quit and lengthening your life. Good luck.
Hi
Welcome to the MedHelp forum!
You could be having smoker’s lungs. This also causes phlegm with black particles. Asthma is an allergic condition and can happen in response to an allergy to smoke. You could also be having this. Chronic cough and removal of phlegm can cause extreme weakness and lethargy. Drink plenty of fluids to keep yourself hydrated. Also other causes like anemia, diabetes, thyroid disorders, chronic fatigue syndrome etc will have to be looked into. It is difficult to comment beyond this at this stage. Do consult your doctor. Take care!