So sorry your dd is suffering over this. I was so perfectionistic about my grades, especially as an undergraduate that I lost all appreciation for truly learning the material. I liken it to a type of achievement anorexia. The more I excelled, the more praise and positive reinforcement I got...thus, the more I pushed harder to excel, the higher my own expectations, the more I excelled...

I think it was incredibly difficult for me to understand that sometimes teachers just don't "get you" - and may not like you or appreciate your perspective. And they will be impossible to please. I couldn't help but feel their disapproval was a judgement on me as a person, not numbers or words on a page. And I didn't have that delightful "screw you" teenage thing ( which is really an amazingly useful shield).

Hopefully this teacher grows a heart.