You have to think creatively. You may not be able to eat like normal. You need proteins and carbs. Proteins can be peanut butter, eggs (stay good well after date), cheese, lunchmeat/hotdogs, canned meats and fishes, fresh meats to freeze. Loaf bread is useless. Crackers, chips, tortillas, canned biscuits make a substitute that lasts longer. Canned soups/tamales/hashes/chiles. Frozen meals if you have freezer space. If you can get flour, also get oil because you'll need it. Get any kind of soap at all. Don't worry too much about veggies unless you can easily get them–focus on long lasting protein sources and carbs. Throw in some real butter.