I'm not sure if this is an allergy "attack" or the beginning of a cold… but I have a burning in my left sinus area, the constant urge to sneeze, lots of sneezing, and my nostril on that side can not stop running. I took generic zyrtec about 1 ½ hrs ago, a

See a doctor. Burning is not a common symptom of sinusitis. The fact that it is unilateral (one-sided) is not typical for allergic rhinitis. I would strongly recommend you see an ENT doctor for appropriate diagnosis to rule out the rare but possible presence of nasal polyposis. The only documented technique of proving sinusitis in a CAT Scan of the sinuses. Zyrtec, an antihistamine only inhibits histamine.