Help please. Use it for a month or not?

I had pharyngitis because of post nasal drip before,all of my reports are normal even IGE and eosinophils counts too...now pharyngitis is gone but still i have a post nasal drip and minimal mucosal thickning in right maxillary sinus,i had consulted an offline ENT for this and didnt got completely relief i had completed his course but i got frustated by post nasal drip and mucosal collection on the back of my throat i had used all medicines Bro-Zedex too but i didnt got the relief so one online ENT has adviced me to use Duonase nasal spray for one month because it all started because of 2-3 times constant sneezes after waking up and stuffy nose.so please tell me that can i use it for a month or not?each ENT is saying that it is normal but mucosal thickening and post nasal drip is getting frustating now. E.g: i had used Xylomist nasal drops for 3-4 days and otrivin adult oxy fast relief for 3 consecutive days.