During the practical exam driving fear you may ask the examiner for a time-out, for example for moments when you do not know what to do or have a blackout. This way you can come to yourself again and then continue the ride. In addition, the examiner can also use the extra exam time to repeat a specific part of the lesson that he thought did not go well.
That way you get another chance to prove yourself. Moreover a performance anxiety exam is given by a performance anxiety trained examiner.