I don't believe we need to overcome our fears by dominating them and warring with them.
Our fears offer us an education. Maybe you can get up and acknowledge that you are too scared to speak, so you aren't going to make a long speech. THAT would help a newcomer, to know that they can be introverted and not smooth public speakers and still have continued success. Or ask your sponsor to speak on your behalf and acknowledge your fear.
My experience with speaking has been that it's a skill, and the more practice I have, the less I worry, b/c I have some competence. But I'm still an introvert, it'll never be my favorite thing to do.