How the leader can act in case of of feeling nevrous during speech?

Perhaps the answer is within the question? Please let me explain...

A good leader should never have to 'act' - he or she will be fully authentic in every moment. That is to say, he or she will respond to situations as they arise, but what they will have already is this;

1. All of the relevant facts pertaining to the presentation / meeting
2. Belief in the process
3. An innate sense of trust and confidence
4. Acceptance that sometimes things go wrong

There are also techniques which may help you to stay focused during the speech or presentation.

Dear,

At the end leader is a human being and under pressure he can feel nervous , sad ... what should he\\she do ,he\\she should steer his\\her feelings to deal with such circumstances and to avoid the embarrassment and give himself\\herself a chance to continue .

Anyways , sometimes specific situations or events let them stressed , so they get a moment or few minuets to recover himself\\herself and change the topic for a while then return with new tone to finish it.