How do I stop foot pain from my extremely wide feet?

Ask your school nurse what her opinion is, and if she agrees with you, then you'll have an adult's opinion to help you convince your parents that you need to see a podiatrist. You didn't say if you're fit or fat, though. If you need to lose 20 or more pounds, then something like that can make your feet hurt just from lugging around the extra pounds. Look at the entire picture before blaming just your foot structure. Maybe you could also offer to pay for the podiatrist's visit if that is an issue. Good luck!