It may have been a sinus infection, but the headache started once all of
the congestion was GONE!
The CAT scan showed an abscessed tooth
on tooth #14 (upper left), same side that all my pain! So, I had that tooth and two upper wisdoms removed on Jan 23rd.
A little history on #14. That tooth had a root canal done when i was in my teens (now 34). The abscess had been there for YEARS, as it would get a little pimple on the gum and would go away... I didn't realize the danger in that.