So true! Thanks for acknowledging this. I think too many people think it is just them.
One thing I have found very useful is repetition. Running through what I’m gonna talk about several times and visualizing the whole thing has calmed my nerves.
Also, teaching! By teaching as an adjunct professor at your local college, it gives you practice sometimes 2 or 3 times a week. It has always been the best way for me to be able to do larger talks in front of 1000+ people.