Remember this: most people are there for what you have to say, and don't really care about you.
Exactly... most people get nervous because they are thinking too hard about the impression they may give about themselves or something.
People in the audience are there to "listen".
So the bolder and stronger you start off a presentation, the easier it gets just that much quicker for you. And of course the more times you can do it like that, it gets that much easier the next time, and the next, and the next time, etc.
I get nervous as hell before I publicly speak like most anybody does .... so as soon as I open my mouth I kick it off strong and it just rolls on out from there.
Do I like to do it? ... Nah.... But can I ?.... sure.
So keep your mind on the overall presentation itself.