Because I don't feel worse than I did yesterday, I'm pretty sure this is not the flu. The weirdest symptom is slight dizziness. If I walk too fast or turn my head too quickly, I have a couple seconds of dizziness. Scrolling too fast through computer screens causes the same result. Sounds more like an ear problem (though my ears don't hurt) or maybe it's related to the pain in my sinuses.
I'm going to try hot compresses on my face and saline rinses. Regardless, I think I'll recover quickly since I don't feel worse today.