I have severe food allergies. Nuts. Fruits. Dairy. Wheat. Soy. Corn. Milk. Basically. Everything I was tested for. How can I eat healthy?

Food allergies. This truly is a question that should only be answered by your allergist and nutritionist. You could put your life in danger by not having a strict diet. It may not be what you want to hear, but it's right. Stay healthy!
Not ... Simply because you have tests showing potential allergy to a food does not mean that you will necessarily react to it. You need to see a board-certified allergist to help you sort this out. B y the way, be sure that the tests done were not igg antibodies which merely mean that you have been exposed (not allergic) to that food.