Public speaking. What should i do?

I can understand that it must be very hard on you. Anxiety is an usual emotion, however in excess and to the degree described by you it hampers your performance and mars your confidence. I would suggest that you should seek a consultation with a psychiatrist so that he can evaluate your condition in detail. These symptoms as described by you could be a part of Social Anxiety Disorder or Anxious Personality most likely, however lesser possibilities like depression, thyroid abnormality etc will require to be ruled out. Don't hesitate to seek help, your condition can be helped and such surges of anxiety can be controlled through professional help. In the meanwhile the following steps would help you- regular sleep and exercise, regular meals, avoid use of alcohol and other substance, regular walk, yoga and meditation, maintaining a thought diary etc. Also it would be useful that before any such anxiety provoking situation you can rehearse the situation before a mirror to calm yourself. As I understand such situations are likely to present before you at all walks of life and will hinder your performance at crucial tines, you must seek help at the earliest. Hope this helps you..