One of the basic “secrets” of speaking and relationships is to concentrate on the other person. It’s hard work but try to forget about yourself — how you appear, how you sound, what people think of you — and think about what your audience, or the other person, hopes to get from you. Prepare yourself by wishing or praying or thinking (or however you do this) that you will be able to GIVE something to the other people.
In person, you want to listen very hard to people, ask them questions, and then respond to exactly what they’ve asked. The thing is, everyone is thinking more about themselves than about you. So keep their attention on themselves, and focus on their needs instead of on your fears.