G.♣.
Well, I'm no doctor!!! But I did experience something similar. I did have a CT Scan (thank goodness for health insurance), and was diagnosed with sinusitis. I thought, wait a minute. Isn't that the same thing as "sinus infection?" My doctor said, yes it is, and that's really what it is. He said most often when people think they have a sinus infection, they really just have a bad cold. But pain like you described is often a true sinus infection. The good news is I just kind of had to wait it out like a cold.
Hope it's just a sinus infection. And I hope you feel better soon!