Panic attack? What was it?

I’m hugely afraid of heights. Today, I went on a school field trip with my class to a theater & we got seats so high up & close to the railing which overlooks the bottom seats. While going down the stairs to our seats, I literally started tearing up cause of how scared I was, my palms were sweaty, I was reacting to any touch that someone would give me because I thought I was going to fall. When the intro started, I was watching a girl and I got dizzy. We just cake out for a lunch break & we have to go back in after. Idk how to cope or to not be scared. Idk what happened back there but it was not fun. What can I do?