Check your doctor while it's still early. Mine does almost the same. But the back part, I have mild scoliosis (curvature in the spine.)
Your's might be different, but check to your doctor because when you get old it'll be worst.

It might be growing pains, but go to the doctors to be sure if it is.

Please see a doctor. Make an appointment tomorrow. It's probably nothing serious, but if it IS, you want to catch if as soon as possible.

2-3 years? Eek! Puh-lease see a doctor ASAP. You'll be so glad you did, guaranteed. :) :)

It sounds like you might have hyper-glycemia, low blood sugar, maybe even a type of Diabetes. You should check that out with a doctor, you may even have mono, i'm no doctor, but there could be many possibilities, you should get that checked and have some blood tests taken. Good luck!

You should definitely consult with a doctor regarding these issues. Have you spoken with the school nurse about your concerns? Do you drink water and milk in sufficient quantities? You're at a tough age where some of these issues are part of the growing process.

Don't try to self diagnose these things as getting good professional advice from a trained physician will help you along.

Can't tell if you're male or female, but you might want to have your testosterone/estrogen/thyroid levels checked in addition to looking into whether you might have some food allergies. Best to learn about these parts of your physical body than waiting too long.

Good luck to you and know that there are always answers out there, you just have to be patient and keep looking/learning.