Peanut butter is not classified as a nut. Peanut butter is in the legume family. Also, people with nut allergies can often eat seeds. Just something to keep in mind. Hummus is great but is usually made with tahini, which is ground sesame seed paste. there are beans spreads you can make to go in sandwiches, or apple butter to try on toast. Have you ever cooked apples with cinnamon and sugar to get them soft, then spoon them over some toast? Delicious! Even plain applesauces is nice over toast.
Here are some foods you can ask for your family to buy for you that are inexpensive and widely available:
canister of oats
box of raisins
canned or dried beans (garbanzo, black beans, white beans, kidney beans, red beans, lentils, navy beans...)
cans or jars of salsa
cans or jars of tomato sauce and paste and diced tomato
package of tofu
frozen or canned fruits, applesauce
all purpose flour, whole wheat flour, cornflour
rice (brown, white, wild etc)
sweet potatoes, potatoes
dried fruit like bananas, dates, coconut flakes
cider vinegar
pure baking cocoa powder
You can make your own mayonnaise blending silken tofu with cider vinegar, spices like turmeric or garlic powder, and a pinch of sweetener. You can make chocolate pudding blending tofu with cocoa powder, banana (optional), and a little plant milk or water, maybe a little sweetener.
there are a ton of vegan pancake recipes on the web and even on here that you could try. Everyone loves pancakes. I'll bet your family would eat them. Banana pancakes generally do not even require an egg substitute because the banana acts as the binder. And banana bread can very easily be made vegan and there are a ton of vegan banana bread recipes out there that require only simple ingredients. I found Vegweb to be my best friend as a database of vegan recipes that tend to be more mainstream and not too far out there with ingredients.
Just do the best you can under the circumstances, and don't worry about labels.