I've been driving more than 20 years and almost none of the anxiety I experience because of it ever went away. If I know the roads already it's a little better, but every single day I have to power through the anxiety to get to where I need to be going. It doesn't get better.
Hotels give me anxiety even though I actually lived in a hotel for six months.
My husband developed anxiety later in life doing things he has done for years.
What you're talking about is just normal human emotions, when people refer to "performance anxiety" they are usually referring to an anxiety disorder. Crippling anxiety that doesn't spontaneously resolve.
If you're in your 50s and it's still a constant problem, quite possibly not.
Again, people aren't infinitely malleable, and don't all fit in standard packages.
Even seasoned stage performers often face crippling anxiety before performances late in their careers. Others take their own lives, often at a young age. Dick Cavett is among those who've suffered crippling depression and taken extended leaves due to it.
If you don't have a source, you can simply say so.
At this point, I'll simply presume as much and move on.
Just like if you're nervous about driving on the freeway, or flying in an airplane.
Heck, I remember buying my first phone answering machine. I froze up repeatedly trying to record the message. After a while, that problem went away.