I have this problem too. I have had a recurring dream for at least a decade. I don't have it all the time, but when I have the dream again, it messes me up for a few days. I don't even like thinking about it much, for fear I will have the dream again.
It's not violent, but I am lost in the same place (my old high school, but it is not my high school, it is a huge maze) and I realize that I shouldn't be there, so I try to get out and there are tons of people there who don't pay attention to me and won't talk to me. They are busy.
I finally make it out and then I cannot find my car because the parking lot seems to go on forever and it's filled with cars. I wake up frantically and futilely trying to find my first car. I have no idea how old I am or who all the people are. I am just scared, helpless and frustrated.
I have slight variations, but it always is about the same.
When I was little, I had the same problem but a different nightmare. I was being chased by some man-monster in a public place (like a mall, etc) but no one could help me, no one tried. As the thing bore down upon me, I would try to scream, but nothing would come out. It was in this terror of being unable to scream that I would wake up sweating. I was not yet in kindergarten, but I remember it too well. It happened often.