Welcome to Health Care Magic.
I have gone through your query.
Based on the information provided, the fouls smell from your nose is due to a condition called Atrophic rhinitis
, which in your case is secondary to chronic sinusitis
The pus from the sinus enter the nose and cause inflammation of nasal structures leading to dryness and thick crusts from nose. The thick crusts also cause foul smell and sometimes bleeding from nose.
Treating the primary cause will solve the issue. In your case as he primary cause is sinusitis, it can be treated either by antibiotics or sinus surgery
Meanwhile apply glycerin
mixed in 25% glucose solution to your nasal mucosa to get red of the smell.
You can also use Nasivion saline nasal drops.
Steam Inhalation helps you in relieving sinusitis to some extent.
Please see an ENT specialist
and take his advice on treatment and decide whether to go for surgery or medicines.
Wish you a speedy recovery.