One cause of speaking anxiety is the feeling (and self-directed pressure) of having to impress the audience.
Maybe this occurs to you while you're writing, and you start inserting big, formal or flowery (aka "speechy") words you normally wouldn't say, but that make you sound smart or important.
Or you're on stage and -- suddenly -- it occurs to you that your normal words, actions and movements aren't good enough.
Suddenly, you don't know what to do with your hands, even though you were just having a conversation off stage and your hands were fine.
Suddenly, everything is wrong with you. Your clothes aren't right, your voice isn't right, your humor isn't funny enough.
This is why you hear people over-formalizing their language, like using "he and I" incorrectly or saying the letter "a" instead of the word "a," because -- suddenly -- "me and him" and the word that sounds like "uh" don't seem right any more. Even if they're absolutely correct. (Please read those two blog posts. I beg you.)
We stiffen up. We stop moving. We clam up and stop being our normal boisterous or wacky selves. We act like we're at a formal dinner and don't know which fork to use. And we move like we're wearing a too-tight tuxedo or full-body Spanx under an evening gown. We second-guess ourselves; we doubt.
This need to be impressive is killing your presentation.
It makes your PowerPoint boring. It makes your voice dull, your movements forced, and your facial expressions stilted.
Who ever said that giving a presentation was akin to being a guard at Buckingham Palace? A lot of speakers certainly act like it.
You don't need to impress anyone. Embrace your unique qualities. Have a conversation with the audience. Get to know them and let them get to know you. Have fun with it: bring the energy and enjoy the connection. Be free. Be real.
Save all that formality for the next time you're invited to a state dinner with the queen of England. That's when you'll really need it.