I'm about to jump out a window or something T__T

I'm about to rip my head off. I am SO FRIGGEN STRESSED and I'm betting any of you guys out there that are in high school know the kind of stress I'm talking about. Today I have my friggen ENORMOUS science test that could either bring my grade up enormously, or drop me and make me fail the class. This test has NEW YORK and JERSEY riding on it. LITERALLY.
I'm freaking out and I'm cramming as much info into my brain as possible and I seriously feel like I need to jump out a window or something, or scream into a pillow. I already have anxiety and paranoia, and this is making it ten times worse.
JESUS!!! AHHHH fudge. I hate to be a stereotypical teenager and rant about: oh my life is so hard because of a science test, oh woe is me, but this SERIOUSLY SUCKS at the moment. I'm scared and nervous out of my mind. GAH.
.....heeeelp.