A very good point discussed in this article that says "Focus on your most powerful Experience" when you feel nervous before your presentation. Thinking about positive experiences helps to divert our mind from fear of speaking.
This article explains that the fear of public speaking of most people is going to give you the edge in front them if you learn to cope with the anxiety.
Sometimes, knowing that you SOUND confident is all you need to start actually FEELING confident. Good concrete tips, including one of my favorites about avoiding "uptalking."
Deborah Grayson Riegel provides some insights about public speaking anxiety and how to overcome it with some simple and powerful steps like: breathing, renaming our emotions from scared to excited, among others.