I've been in my house all day. This is a sinus headache. No sneezing, no runny nose, no cough, no itching, no watery eyes. Just headache and nose is stuffy, which is basically what Sudafed treats. I wonder what else does. Cause most of the allergy medicine I have in my cabinet doesn't treat that stuff.
Stop by your local doctor's office. I've fought allergies for over a decade, and have tried everything.
Diet & Exercise does play a major role in a healthy immune system; riding a road bicycle helped me (instead of the motorcycle). Cut back on processed sugars, red meat, and sodas/alcohol (which is a challenge at some events).