hi there, first and foremost as you know you need to stop smoking
,secondly do get an x-ray chest done to rule out any lower respiratory tract
infection and thirdly on the advise of your attending doctor you should start taking a course of anti-biotics to take care of your upper respiratory infection
. You could use steam inhalations and warm saline gargle to relieve you of the chest congesion.You can also take an inti-inflammatory tablet to relieve you of the pain and soreness in your throat. Besides all this you will need a course of antibiotics so do visit your physician and get it prescribed. Take care.