Erk, presentations. I'm sure you'll do fine - if you believe that you can. What's the presentation about? I bet you'll just end up surprising yourself tomorrow morning. Try to look at people, if possible. If you look at the floor, you'll only be imagining the worst possible reactions. You didn't say how many people you're presenting to - is it many? Marie is right - no one likes doing that sort of thing, so the others won't be feeling all that much better about giving theirs. I worried for months about a presentation once - and I was terrible, as far as I was concerned - but it didn't matter. It was over, and I got a good grade for it. The mistakes you make won't matter to the others. You might slip up and think about it for weeks, but everybody else in the room will soon forget, once it's their turn to speak - if they even noticed at all.
It's best not to worry about it - be prepared, but don't worry. I had a job interview this morning, and I hadn't had
time to worry about it. Near-zero anxiety, seriously. Find something to keep yourself busy now, and you'll be more calm when the time comes.
Good luck with it - you'll be all right.