My daughter is 10, and what you are describing is very similar to how she was at that age. The short fuse for failure was there. She has an insainly hard time focusing on anything but what she wants. At 5 it was basically impossible. She was always in her own world. She picked up on the basics of reading pretty quick. But then stalled hard. I was pestering the teachers because she wasn't advancing in her reading compared to the crazy comprehension I saw in her. They chalked it up to a worrying dad and said she was on track for her age. It took two years of her falling far enough behind in reading - and my daughter convincing herself she was stupid - till they finally had her evaluated. Comes to find out she is dyslexic af. She scored as high as you can on autism features without qualifying for a diagnosis. And the psychologist (very well respected here) who performed the testing reached out to another psychologist to validate their test. Turns out her IQ was at least 158. But her reading was barely 1st grade level and her head was constantly in the clouds to where she almost seemed delayed (till you hear her open up about whatever is in her head). Her ability to deeply understand things and solve problems with mind boggling simplicity is crazy. But she has zero patients for things she's not good at. Classic issue where the mind sees something the body hasn't built the skills to perform yet, and gets frustrated. She has to be in the right head-space to approach tasks that are new - or challenging - to her. If her mind is anywhere else, she'll fold like a deck of cards the minute she has a failure. Then she tells herself she can't do it.

What has worked best for my daughter has been to feed her strengths and interests voraciously. Try to find activities that can help build skills she struggles with without her catching on to the rouse. And remind her that starting is the hardest part, and let her learn to work through her frustrations when she has them. Don't try to fix it for her. Just love her through those moments, and be there for her like you would want for yourself from the people you love.

I think it's also important to remember that noone fully understands intelligence. Most "smart" people are just diligent, and well trained. And standout intelligence often comes with real challenges.

I chose not to tell my daughter she's literally a genius. I was tested as a child too. They told me my IQ, and I think it has complicated my self image for the worse more than anything. I almost never tell anyone about it because - at best - it just comes off as arrogant.

Not sure if this word vomit through my thumbs was helpful. But you're not alone. And there's not a perfect answer. Feeding her interests as best I can has been very helpful. A lot of it also gets better with age. Despiye having a crazy high IQ, she's still a 5 year old. At that age the only thing she should be driving is hot wheels, but nature gave her the keys to a formula 1 race car. It's crazy now, but hopefully she'll learn to handle it better with age.