hello and welcome to HCM,
I do understand your concern both towards the surgery and towards the medication.
As far as your surgery is concerned it is clear that your doctor has done
septoplasty along with FESS. But if you still have
post nasal drip then your sinuses have to be cleared again using
endoscopy. Since you also have
snoring, it is also clear that you have nose block in addition to your problems.
You may start a course of antibiotics to first clear your sinuses such as amoxycillin-
clavulanate 625 mg twice daily for five days along with the anti
histamine which you have mentioned. Your doctor will know about this.
Xaria is levocetrizine and is a very safe drug which can be taken for long periods without much side effects in the usual course. You should however understand that any drug can cause any side effect but this one has been known to be relatively a safe drug so do not worry.
After the above you must get yourself checked by an ENT who will perform endoscopic cleaning of your sinuses
Also do steam inhalation and start anti reflux treatment (tablet
pantoprazole 40 mg twice daily before food-your doctor will know about this)
take care
Dr Sriram Nathan