My right sinus is constantly draining. i cannot drink milk or any dairy because it immediately clogs up my sinuses and i am constantly blowing my nose?

How do you know?: Sinusitis can not be diagnosed by a patient. It really sounds as if you have allergic rhinitis and the etiology may be dairy products. The drainage is most likely coming from the right nasal cavity. You also may have a nasal polyp. Get a diagnosis from an ENT doctor or an allergist. The gold standard for a diagnosis of rhino-sinusitis is a cat scan.