My long term foot problem?!

Definately go back and see if you can have an MRI done. That will show the doctors your foot in great detail and probably expose the problem. In the mean time, ask your parents to buy you some crutches so you don't have to walk on it. Don't just leave it how it is because obviously you're miserable.

you didn't say exactly where the pain is coming from on your foot, but 4 years is a long time to have to deal with it, and the doctors not know what it is, so it could be a stress fracture that is border line, and hasn't healed right, or if you do sports, and it is behind you foot going up to your ankle it is an achilles heel strain, and you keep pulling the muscle there, and resting it usually will make it feel better, and ice really only works at the onset of the original injury, and switch to a heat wrap, so try a heat wrap, and there is a gel called artica gel, that you can buy at any health food store, that is harmless and could help ease the pain while it heals...if you can wrap it in an ace bandage too, that usually helps your foot to feel better due to the support..hope this helps..if not make another appointment with a foot specialist from a sports clinic and see what they say..