I have been lightheaded for about a wk w/a weird brain freeze-like headache on&off. today i have pressure in my forehead. i flew the day it started?

The change: in cabin pressure especially on longer flights can cause a number of "disquieting" symptoms following the flight including some microscopic "leakage" of cochlear fluid (causing vertigo, light headedness etc") sinus pressure alterations (frontal sinuses=forehead pressure) especially if you had a mild cold, or allergic congestion) Hope this is helpful Dr Z