Most courses require students to give a presentation at some point during their studies, for many the prospect fills them with dread. Unfortunately or fortunately depending upon your perspective, the inherent nature of graduate jobs means that at some point there will be a requirement to present to or address an audience.
The prospect of presenting is so distressing for some that they waste too much time worrying and vital preparation time is lost. Worrying is counter productive, so you must put it out of your mind.
The fact is that confidence is a great antidote for nerves and a presentation that is well researched and properly prepared will give you that confidence.
The opposite is also true. I have known students who have been so side tracked by fear that they have been unable to concentrate upon the task in hand leading to sub-standard preparation, in turn promoting a lack of confidence which equates to increased nerves.
You need to break the cycle! Focus on the work and the nerves will to a greater extent take care of themselves. Don