It is because of accumulation of mucus discharge.
Welcome to Health Care Magic
I reviewed the history.
It seems you had severe bronchitis which was treated by antibiotics and later by one more antibiotic in the form of Azithromycin and the present complaints are bad smell in the nose.
The common cause for bad smell in nose is accumulation of mucus discharge as a result of post nasal drip
seen in respiratory tract
infections or because of obstruction of the sinuses.
Since you have mentioned that last year you had a sinus surgery
for blockages the sinus infection
and accumulation of the secretions is the most likely cause in your case.
The treatment of the condition is by using mucolytic drugs and decongestants drugs.
The other causes needs to be ruled out in case of complaints of smell from nose are atrophic rhinitis
. Do discuss with your doctor when you go back to him tomorrow.
Hence no need to worry with treatment to dissolve or to remove the accumulated mucus secretions the condition can be treated effectively.
Hope the information is helpful to you.