It is "stage fright" or anxiety from stress. Perhaps the name you are looking for is "Psychoneurosis?"
It is unlikely to be psychoneurosis. Anxiety would be a better term.
If you are performing in front of others rather than alone, your level of learning of the task makes a difference in your performance. For those tasks that have been overlearned, performance will be enhanced. However, if the task is not overlearned, you will be likely to have problems.
Overlearning involves continued practice, even after you think you have learned a task. This is done with martial arts and athletics, but most students do not do this with academic subjects. Overlearning is retained better than just learning a task, especially under conditions of stress. The stress can be performing in front of others or even taking an exam. (This is why cramming is not an effective method of study for students.)
This reminds me of the old joke:
"How do you get to perform at Carnegie Hall?"
"Practice, practice, practice."
Anxiety disorders (which used to be included under neuroses) are not indicated unless the anxiety is persistent, lasting 6 months or more.
I hope this helps a little more. Thanks for asking.