First of all take a deep breath.....you have lots of time to prepare for this and I am 100% sure that when your class learned about the presentations, about 90% of them instantly started to panic. I really think that you need to take the bull by the horns here, prepare, give it your best shot and keep thinking how proud of yourself you are going to be when you do this. I bet that it will be way better than you imagine and you really won't be the only nervous person there, I am sure that everyone will be relieved to get their presentation over and done with