How many people here have sinus allergies? This is a bad time of year for allergies, believe me. Last night I had a heck of a sinus headache, worst I've ever had. Pain across my forehead, behind my left eye and even on top and back of my head, sharp pain too. I don't know how I even got to sleep but when I woke up this morning it was a lot better, still some lingering pain though. I just took some more benadryl allergy and I hope that will clear it the rest of the way up.