What Causes A Feeling Of A Foreign Body In The Sinus?

I am a 34 year old female, height 5'1", weight 116 lbs. I am experiencing pain and the feeling of a foreign body in my right sinus, which moves from my sinus to the top of my uvula; difficulty swallowing regardless of substance; the feeling of a lump in my throat; stabbing chest and abdominal pain; the feeling of fullness & pressure in my right ear and throbbing sinus related headaches. All of these symptoms are prior to accidentally breathing in an unknown foreign object into my right nostril a week ago. I have been to three different GPs who were unable to locate a foreign object by examining my ears, nose and throat. I've had an endoscopy and CAT scan that have both yielded normal results. My symptoms are progressively getting worse and are affecting my ability to eat, sleep & function.