Allergies maybe? Sounds like it could be inflammation.
If it keeps up see a doctor, there are viruses that can attack the brain, no joke.
too much caffeine, brain burn(similar to heart burn), brain freeze, withdrawal, ibogaine blocking the drug receptors in your brain, these are all options.
Too much coke in that last line.
That cannot be good did you eat anything?
I would start drinking lots of water and see some help.
While unlikely it might be mercury poisoning.
Because im on your mind. ;)