I made the most silly mistake anyone with blonde hair could make ever. I am a natural blonde and died my hair black with permanent hair dye and now I hate it. I want my natural colour back. How does hair stripping work and how much would it cost by a pro?

It will need to be bleached out. I'm not sure how much it would cost as the prices vary. A cheaper alternative would to go to a hair/beauty college or school to get it done. And don't worry about them messing up your hair, they wouldn't be allowed to do it if they weren't capable. ;)