Hello,
I understand exactly what your talking about.
I have been there, stood up, totally prepared with my notes and turned beet red, stammered and stuttered and cried.
I was on Paxel for awhile for anziety, for about 2 years I took a low dose and it really helped keep me calm. Been off of that for a year now and doing fine.
And, this might sound weird, but Online Voice chat rooms helped too.
When I first started trying to "step up to the mic" even to say hello in this "faceless" type of chat I would have the same symptoms, but after a period of time , because of the non-face-to-face structure, I gained courage and began to talk...... and talk and talk and talk..LOL
It has helped me out a LOT in the "real world" as it gave me my voice back in a safe environment.
One other thing that still helps me , and that is what I call "role playing" and that is to place yourself in the role of the kind of person you want to appear to be(even tho you might not think your that type of person it helps take the pressure off of "YOU" and helps you to think about "playing the part" instead of thinking about your audience and their reaction to you.) Just Act like the person you want to project, and once your done ,after all, it was you the whole time!*S*
If all that doesn't work, Humor is medicine for the anxious soul. One good line, even about how nervous you are, IE. "If you should happen to hear a knocking sound through my presentation, please pay no attention, as my knees are just makeing sure I know their still there!" (I know that one is corny as all hell but you can think up your own)LOL
It makes your audience aware of your nervessness in a lighthearted way and they will be sympathetic and will actually project positive, encouraging looks your way.
After all, 9 times out of 10 they have been in your shoes at least once in their lives and can relate.
GOd Bless!
Sorry so long,
Gina