Pressure in face, nose, upper mouth when bending over. no sinus drainage. could it still be sinusitis? i have a deviated septum, could that cause it?

Sinusitis likely: One can have a collection of mucus within the sinuses that are unable to drain leading to inflammation of the mucosal lining of the sinuses, and possibly bacterial collection. Sinus pressure can occur due to lack of drainage and become exacerbated when bending over. Your history of a deviated septum could be adding to the difficulty with sinus drainage. See PCP for treatment.