dear user about your question i would like to tell you that smoking is risk factor to have throat congestion that you feel and this is the first possibility second possibility is to have throat infection viral or bacterial first step to do you should stop smoking that bad habit harm your body alot and cause irritation of your throat and mucus production is due to allergic reactions to smoking....so please you can stop that for aperiid of time and see results....you should also drink alot of fluids that will make you feel improvement if symptoms persist after stop smoking you should refer to your ent doctor to examine your throat as you may need to do throat swab to detect causative organusm that cause infection if bacterial infection detected you will be described antibiotics as amoxicillin for ending this problem........and dont forget to drink alot of fluids...... .....wish you happy healthy life