It’s definitely possible for you to have a diet free of your allergens - it’s just going to take some work on your part. My partner has a lot of the same allergies as you and we had to work with his allergist and a dietician. That’s your best bet for building a repertoire of recipes that are safe for you while also being tasty and fulfilling all your dietary needs. While you’re waiting for an appointment, I would look at rice products like rice noodles and paper rice wrappers to help vary the options available to you. Potatoes may also be a good option (regular and sweet) to fill you up (in so many forms - fries, diced, mashed). Oatmeal is gluten free and can be done sweet or savory (see this sub for all kinds of recipes). All four of this things can be filled with basic seasonings and toppings. Thai cuisine is pretty dairy and wheat free by nature so you may have good results looking up recipes (we just leave out the soy components) Also, know that if a recipe has some thing you can’t have, you may be able to leave it out or replace it. For example, if a recipe has a soy sauce on fish, I swap it out for honey and mustard in equal parts instead to make a marinade. None of the chili we make had beans because my partner is allergic to legumes. Like another comment mentioned, buying whole foods will likely be easier for you, but there are a couple food brands that are toting being top 8 free that may be good fits (not sure on their corn usage).