Believe me, the anxiety
you are talking about is a universal phenomenon. Everyone while facing any gathering ,irrespective of the size, the age and the experience of the group gets butterflies in the stomach.
It is something innate to human nature and in a way it prepares the human body for such challenges. The best way to overcome is to rehearse as well as you can. Give your self a good practise in front of a mirror, deliver in front of family members, look for areas of improvement
To boost your morale visualise yourself excelling .Watch your role models performing. See motivational videos ,read inspiring quotes, anecdotes or books. Avoid the company of negative people and see yourself realising your dream. Believe in the fact, that we receive what we dream.
You can take personal advise from a counsellor as well.
You can do it. All the best.