SCARED!

I'm so scared.. I don't know anything for the test, and I've just started thinking that maybe I shouldn't go tomorrow to my school.. REALLY! I don't know what to do? I thought that studies will be the most amazing time in my life, but it is the worst time, i'm so stressed every time when I have to go on classes, because I'm never prepared, I don't have the strength to learn.. I think that I've made a HUGE mistake choosing this University, or this course..