Frequent colds (urti) It's use?

Sir, whenever there is a change a change in climate, I got cold very easily. It takes relatively longer time to heal with the help of antibiotics and antihistamines. Occasionally I got a nose block and sneezing in the morning. The phyrings area is reddish and granular throughout the year. From Feb to July it is ok, but the next six months it makes my life hell. I got 6 to 8 bouts of respiratory tract infections in this six months span. Doctors prescribed metaspray alongside monticope tablets for management and told it is because of seasonal allergies. Now, I want to know whether it is the right treatment, or some better options available? Because I do not find this very much helpful. How do I confirm the allergens? Please suggest some other course of treatment. How long can I use monticope and metaspray safely? When should I stop it's use? I use it almost daily for those six months, and as and when required basis for the first six months of the year.