I think you should give the speech to your reflection more than a couple of times. Practice makes perfect. Also, know your material, inside out. If you know what you're talking about, you will be far more confident in talking it. Above all, you must relax. Eat and sleep well, be comfortable. Do not spend the last few moments before the presentation agonising over it, instead have a laugh with friends so as to be in a good calm frame of mind.
PS, realise that this is just one of thousands of days you will live in your life and is very easily forgotten. Don't put too much importance on any one presentation, the added pressure is unnecessary.