Let me suggest you look into "twice exceptional" resources. I'm 2xE. When I'm good, I'm very good. When I'm bad, I'm truly terrible.
The very nature of being talented but also handicapped makes it nigh impossible to predict if today you are delivering awesome sauce or laying another goose egg. Given that reality, it isn't crazy to err on the side of charging low rates so people don't smear your reputation if it falls short.
Working on solving underlying problems and putting good systems in place for double checking your work can help. I also prefer to charge by the piece rather than by the hour. Then it's my problem if I stare at the screen and drool on myself all afternoon, not my client's, and as I get better, my de facto hourly rate improves.
I absolutely do not suffer from Impostor Syndrome, but I do struggle to appropriately price my work for a variety of reasons, including the fact that I'm 2xE. It's slowly getting better.
Best.
(Will add: I recently learned that the new abbreviation is 2e. You might have more luck searching that term than 2xE.)