Thanks for posting your query .
First of all you might have heard of Smoker's cough . It is a irritating Dry cough
for weeks to years seen in Smokers .
Now I know that you are having a wet cough with brown phlegm , but your smoking
habit irritates the throat and airway and Lungs. This Irritation increases the chances of having infection, either in Throat or Airway or in Lungs .
We can treat this infection with Antibiotics and it will become al-right but as long as you don't stop smoking these problems will come back . Stop try to quit smoking .
As of your present problem get Sputum Culture
sensitivity test done and revert back with report . You need to be started on Antibiotic as per culture sensitivity report .
Hope you find this information useful .
Any clarification feel free to ask .