See, first of all, there is no permanent cure for allergy! But u can keep it under control with proper medication. Secondly, no matter how good your sinus surgery was, if u dont control your allergy, it is bound to reccur. I suggest you continue taking the medicines. Usually they dont have any side effects. If your allergy is getting out of control, change the medication , but keep taking it. U could also think about allergic skin prick test to know what exactly is causing your allergy so that you can avoid it.

You require nasal endoscopic examination and proper follow up treatment for the surgery you have undergone lest the problem might recur again for which you underwent surgery in the first place.