We also had problems with perfectionism but it was more of a problem with physical things and these problems were exacerbated by people who expected my son to be able to do physical things at a high level like his cousins, who went to the same school he went to for kindergarten and who were physically gifted and very talented in football which is what really counts as gifted in our small town. My son felt very different even from his own family. I think he was about seven when he first read about genetics and started asking me if he was a genetic mutation. He did not need adults to point out his differences when he already was self conscious about handwriting and drawing issues. He still remembers how he felt when a very strict Sunday school teacher made him feel bad in front of other kids about not doing something as fast and as neatly as the other kids. She was not the only one to do this. There was also the cub scout leader, the acting teacher, the gymnastics teacher and the swimming teacher. That was one of the things I found to be most upsetting and hard to deal with. My son needed encouragement instead of criticism and he reacted to criticism by becoming very reluctant to write or draw or do crafts or anything physical in front of other people. His piano teacher was the exception. She kept telling him he could do it and it was okay if he made a mistake, that it happens to everyone. She saw him on those bad days when sensory issues or anxiety or whatever distracted him, as well as those good days when he was able to perform well. She believed him when he told her he had practiced when he had those bad days and he was trying but he just couldn't perform as well as he should that particular day. It always really bothered him when he felt people didn't believe him.
While my son can spell very well orally and he spells very well when he types, he sometimes leaves out a letter when he writes words. It is hard for people to understand how a kid who learned thousands of words in preparation for a state spelling bee just a few years ago can misspell an easy word or not capitalize a word that he would capitalize if he were typing. It embarrasses him sometimes, but he can usually make a joke about it and move on now.
When he first started preparing for the spelling bee he found it helpful to use familiar tunes and sing the spelling of difficult words, but after a few months it was like he had somehow trained himself to notice the tricky parts in words. He could remember how to spell difficult words that were flashed on a screen.
At 11, my son is very aware of his strengths and weaknesses and he knows that he can do things well enough with enough practice even in his weakest areas. Success takes the sting out of knowing he is less adept at other things. He was very proud of himself when his very coordinated, former cheerleader sister listened to him play the very challenging song he has been working on for the recital and she told him he was better at piano than she was.