If I can do this (be a CFI) I think just about anyone can! I too have an irrational fear of public speaking but have found if you are prepared and more importantly passionate about what you are speaking about all the anxiety melts away after the first few words. I can remember my knees shaking when I stood before the white board to teach my first "practice lesson" to the CFI who was training me but the more you teach the more you know the material and after awhile you don't even think about it. After 4 years and nearly 1400 hrs of dual given its old hat. You CAN do it! Good luck to you!!!