Hi,thank you for posting your query on health care magic.
Looking at your symptoms,Allergy might be a cause for inflammation in the Sinuses.The common cause for Nasal polyps is Allergy.
I would advise you to have Allergy testing to find out that to which substances you are Allergic like Certain foods,dust,molds,grass pollens,etc and to take precautions to avoid those substances.
You may find relief by taking following medication:
Antihistaminic like
Loratidine,
Analgesic with Antiinflammatory like Ibuprofen,
Antacid like Rantac,
Oral decongestant like
Phenylephrine and Nasal decongestant drops like Xylometazoline(take only if you are not suffering from
hypertension),
Nasal steroid spray like
Mometasone.
Continue with the netipot cleaning your nose.
Also do steam inhalation.Avoid cold food and dust.Drink lots of warm fluids.
Hope this answers your question.Take care.