I recently found out that my 15 year old son has food allergies. They popped up out of no where. He is miserable, with a rash, itching all over. Besides that, he is allergic to soy, corn and a laundry list of things. I need help, he is used to eating whatever he wants, whenever he wants. He is 6ft 3 and 175, a growing boy. I have to learn what is good for him and not anymore, any advice??