Difficulty breathing - possible allergy.

Hello, for the past 2 months since May 15th, on and off i have trouble breathing through my nose as it becomes very stuffy. There is not mucos or such and my nose is clear, but feels stuffy and difficult to breathe through, which sometimes causes chest tightness, exhaustion, and facial pain also. This comes and goes and i try to relieve it with steam inhalation, vicks vapo rub, and vaseline to prevent dryness. It comes on suddenly and resolves itself gradually over the course of a few hours. I've taken cetrizine a few times and that has worked well too and relieves symptoms within 30 minutes. Since the symptoms were relieved by cetrizine i suspect it may be an allergy but im not sure if it would be food or in the air. My GP prescribe montair but that wasn't very effective. Any advice and is it possible to be tested for allergies through blood test or some other test? For context, I moved to Bangalore 1 year ago and have never had such a problem before in my life.