Sinus infection? This is the oddest one yet.

Yesterday I started feeling like I’d been punched in the nose. The right side of my nose at the bridge feels incredibly bruised. The feeling persisted all night and all day today, but now I’m thinking it might be a sinus infection because my right eye and ear are both hurting. Except for a slight inability to focus (I attributed it to it being Monday), I feel fine. Well, actually, as I type my head is starting to pound.

Usually my sinus infections start with a cold, though, not a bruised feeling nose. Can you get a “sudden onset” sinus infection? Could it be anything else?