High Anxiety speaker

Okay so I've been in high school for 3 years, in my 4th, and over all the presentations I've done, I still can't do a presentation. I get extreme anxiety, sweaty hands and my face flushes RED. its terrible, even if I just have to go up to answer a question, or act out a section in Macbeth or something I can't do it. I feel like everyone is looking at me, and i get so nervous that I just want to run out of the classroom. I sweat like crazy, fiddle with my hair like crazy, and usually i will get so nervous that i just read directly of of my notes or powerpoint. I dont look up from my reading either, because i'm too scared to look at the audience. I hate this phobia, because I know that I can do this. I just get too nervous, and its really embarrassing and I dread any presentation EVER assigned to me. Its pretty terrible. any suggestions? would be nice.