First,practice the speech in front of the mirror.Remeber you are talking to your audience,don't just memorize the speech.It's OK to use juse a few hand gestures if it helps to calm you down.
Second,rehearse it in front of your family and friends and ask them for any feedbacks and suggestions for improvement.
Third,more practices.Remember practice makes perfect.When you know something by heart,you won't feel nervous to present it.
Fourth,take a deep breath before making the speech or crack some jokes to calm yourself down.Be sure to go to the rest room before hand.