I just thought of dropping these lines to add something to the helpful mentiened ideas.every public speaker has to bear in mind that
as a humain being,no one on the face of the earth can proclaim that he or she doesn’t feel afraid of standing in front of a crowd.my point here is that feeling a fraid in such setuation is something purely natural,so we cannot triumph over it,the only alternative that is left for us is to learn how to speak in public while we are afraid.

Preparation is the key to success
Preparation will provide you the required self-confidence. Even with familiar subjects, without proper preparation, you can find yourself in clumsy and awkward situations. To avoid any last minute anxiety and panic, prepare beforehand. However, once thoroughly prepared, avoid last minute changes just before the presentation. Your audiences would rather hear your short and sweet talk instead a long rambling one.