Dear
Welcome to HCM
We understand your concerns
I went through your details. I suggest you not to worry much. First of all, why are you worried about not being able to address a crowd? Everyone cannot do everything.
Secondly, we master every thing with the help of our own experience. Experience makes a man perfect. You are worried about a future happening (being addressing public), becomes anxious about that, thinks about that event (future) every day, and put yourself in future every time and worry. That approach is wrong. Learn to be optimistic.
Thirdly, if you want to learn something, repeat it several times. For a beginning, Talk (deliver a lecture) in front of two or three friends. Then increase it to 5 or 6. Then to 10 to 11, Then in front of your family members, class, office friends,. Whenever you get an opportunity, speak. When ever you get an opportunity, walk across a stage, don't do anything, just walk across, as many times as possible. Do these steps with devotion and your problem shall be solved.
If you require more of my help in this aspect, Please post a direct question to me in this website. Make sure that you include every minute details possible. I shall prescribe some
psychotherapy techniques which should help you cure your condition further.
Hope this answers your query. Available for further clarifications.
Good luck.