If it's allergy's, the good news is that most of your running will be done in early morning while the air is still clam and not so thick.
You will be built up. The pace is slower at first and before you know it your running like a deer. The pain will go away. Just suck it up and drive on.

__________________
"Leave the Artillerymen alone, they are an obstinate lot. . ."
Napoleon Bonaparte