Son is a perfectionist

Hi, I am teaching my 15 year old son how to drive. Tonight he made a mistake and because I had to tell him to stop repeatedly, he got really upset. He is not just your basic perfectionist, he has been seeing a therapist since 3 years old because of it. I know I can’t control his thinking, but part of doing this work is to help manage my thoughts better and try to model that behavior for him and offer helpful thoughts as well. (Just started coach certification). Anyway, here is my model. Any thoughts or suggestions are appreciated. Thank you!

C: son said he should drive/ be perfect
T: He is going to be unhappy his whole life if he thinks that way.
F: anxiety
A: tense up, worry, ruminate, feel sick to my stomach, try to refute what he says, overeat–especially sweets, use food to try to calm down, stay calm on the outside, but feel horrible on the inside
R: I am going to be unhappy my whole life if I continue on this way

C: son said he should drive/be perfect
F: calm, assured, confident

I don’t know what to think or do here. It’s my child and I love him so much and I really want to help him. Thank you!