How bad is a staph infection in your sinuis? and what other problems will it cause?

Sinusitis: Staph is a very common pathogen in a sinus infection. Treatment is not particularly complicated for this bacteria.

Not good, but...: Not too bad. It should be treatable. Staph as a true sinus infection is more common for people with chronic sinusitis. Staph is a frequent cause of infection in the nostril area (which isn't technically a sinus infection). See your primary for treatment, wash your hands before & after touching your nose to avoid spread. If you have a true sinusitis w/ staph, consider ENT consultation.