Try to memorize your presentations as best as possible so that you don't have to worry about knowing what to say. Then if you have a friend in class just look at them during your presentation, and every so often fake scan the room by looking above peoples heads then return to your friend. If you don't have a friend of yours in a class you have to give a presentation then ask someone in the class that you feel comfortable with or trust so that you can look at them during your presentation and fake scan the room. Just try to act like you are practicing in front of your friend or the person that you trust instead of the whole school. What also helped me is that a lot of the kids in a given class are going to be ignoring you anyways because they are either thinking about their presentation or are just bored so you don't have as many eyes on you as you think. If none of that works and time doesn't lessen your fear of public speaking (don't worry you aren't alone, I used to be terrified) then you might want to have your parents to take you to a psychiatrist so that they can give you a prescription for a low level anti-anxiety medication like buspar. I take buspar (not for presentations but thyroid issue induced anxiety) and it is very gentle, there aren't any side-effects, and it really works to calm me down. Plus you don't have to take it everyday, it is a medication that can be used on an as needed basis so you could take it a half-hour before a presentation and not feel so anxious. But till then, don't worry about sounding extremely nervous when you talk because I used to sound like that and I never got marked off for it so don't worry. A lot of teachers recognize that public speaking is hard for some people so don't worry about them.