My Parents wont let me take any form of medicine from a doctor?

Well its more of my dad, he doesn't think its safe, or he doesn't think they know what they're talking about. he keeps insisting that for everything that is wrong with me will be fixed with iodine. He won't let me go to the doctor about my arthritis in my fingers. i now think i've caught athletes foot from him because we're both prone to it and he wont do anything to make his feet better even though he's already given it to my brother, because he doesn't like using medicine. and i want to get rid of it but he wont let me take the anti fungal pills and creams because apparently they're bad for your liver. its been like it is for months now. what should i do?