If it is allergic nasal wash and steroid spray can take care of it. Get a allergy test done and treat the allergy by immunotherapy. Surgery is done if all measures to clear sinuses are exhausted and you have a blocked nose

I suggest you come down to my clinic Y S Desai Specialty Healthcare with all your previous records and CT scan films and CD, for seeking a second opinion.

You can choose any modalities of treatment you want, but the point is if your sinuses are blocked, as would be seen on CT scan, and you're advised surgery then you should proceed with surgery. Surgery is endoscopic,and it's meant to open up your blocked sinuses and improve ventilation and drainage. You can try for medical management first then plan to go for surgery.