Being alone... Last year about this time I would have said that it would have been a tie, but I recently got over my fear of crowds, but that's a story for another day.
Diarrhea... Definitely! I figured out how to suppress my gag reflex a long time ago and prevent myself from throwing up when I get nauseous, so I don't worry about throwing up anymore.
Disappointing someone you care about or embarrassing yourself in front of loved ones