I used to when younger. Anytime I'd be in a place with "organized" people (in a church, in a meeting, etc) I'd check for the exits first before I'd sit down and I'd sit in a place near an exit just in case I felt "sick" or like passing out. It was the thought of embarrassing myself that I feared.
Of course I never fainted in my life, but like you the fear was there. STILL never fainted in my whole life, but after many years I realized it was all anxiety MAKING me like that and if I'd get like that I'd just keep controlled breathing and say, "You are OK, you are fine!" over and over again. Now I can go to a place with "organized" people, not even LOOK for the exits, sit in the middle of the room, and I'm good.