Ct scan neg. for clogged sinuses on doxycycline for sinus infection still, however having horrible sinus pain and pressure what is it?????

Sinusitis: Without seeing and examining you and obtaining further history cannot diagnose you, but you might try saline nasal rinses with a Neti-pot, decongestants and a visit to an ENT doctor if you have not yet done this. Usually one does not need antibiotics for sinusitis. This may be due to allergy or represent inflammation elsewhere besides the sinuses. See somebody soon.