Situational fainting/paranoia problem?

I’m in high school and I have a history with fainting, which usually happens during a health or science class. However over the past couple of years I’ve been somewhat successful in fighting the faint spells. I’m able to remain conscious yet I still experience the dizziness, sweat, and weakness.

This school year I’m taking AP Psychology. I enjoyed the class very much when it first started, but a few weeks ago we watched a video about a man who had a pole shot through his head in a mining accident and lived, and it showed how it affected his personality afterwards and all of that. The video was repulsive and really got to me in a bad way, and I almost fainted.

Ever since we watched that video, I’ve been experiencing anxiety during the class. I’m constantly shaking and paranoid I’m going to have to endure something like that again, and scared that I’ll actually faint again in class and have to deal with all of the negative attention it brings. I can’t enjoy the class as much as I used to and I honestly don’t know what to do about it.