To get rid of our fear and anxiety, it is important to take the plunge. What we fear is mostly smoke and mirrors, something that was bothering us psychologically but had no substance. When we take the plunge, we dispel the self-belief that the task is impossible.
In the case of public speaking, we need to build our confidence by taking the plunge, initially with a small audience, and gradually building it. Start with small steps. It is ok if you stumble.
You will come out a different person when you accomplish what you fear.