Head went from feeling pressure and blood rushing to a painful feeling behind my eye. i am also sensitive to light now i tried tylenol (acetaminophen) what happened?

Headache: Headaches can come in different ways. Sometimes it can be in part of your head and if it is behind your one eye and the eye is tearing it is called "horner" syndrome. It could also be an atypical migraine if you have a history of migraines. If you start having vision issues or it keeps coming back go see your primary care doc for further help!