A: Public speaking fears vary with each individual. There are many factors to consider. First of all, what defines an audience. Is that more than two people? Ten or more? 60 or more? I worked with an individual who would freak out between 6 and 7 people. It was quite amazing actually. As long as there were 6 people he would perform great, but that seventh person had him shaking in his boots. So I had him experiment by working in front of an audience of 6 plus a child, and then 6 plus a baby. Neither one of those two had any negative affect. It was the seventh adult that was the culprit. So that is what we began to work on.
The starting point for you would be to isolate the "trigger point". These less than desirable responses have a beginning, a middle, and an end. I would encourage you to explore the feelings yourself, yet if you feel you need assistance, then work with a professional.
Another area to explore would be your beliefs around your ability to speak, what you have to say (the content), your self-image as a speaker, your feeling towards authority as well as being one yourself, the need to speak up (cultural conditioning about people who say what's on their mind), and perhaps even a belief about revealing a part of yourself and allowing yourself to be vulnerable in front of others.
Explore and have fun!
-Oz