Whenever I have to do this, I find it helps tremendously if I can socialize with my audience prior to the talk, as opposed to just getting a cold intro, and ste

Whenever I have to do this, I find it helps tremendously if I can socialize with my audience prior to the talk, as opposed to just getting a cold intro, and stepping up to the podium. 2000 people is a lot to socialize, but perhaps if you can get some time to chat with people in the front rows beforehand, it may calm your nerves. The other suggestion is somewhat controversial, but a friend of mine mentioned the same problem and talked to his doc about it. He gave him a very low prescription anti-anxiety scrip. He takes it now before his talks and says it works magic. Unfortunately I don't recall the name of the drug, but it might be worth investigating. ..and..practice..a lot.