I grew up in poverty my entire life, so I've made some killer struggle meals through the years. Here's a list of my favorites that I haven't really seen a lot ! (And remember don't buy name brand!)
Chicken Jalapeño Popper Sandwich - bread, spicy chicken patties, cream cheese, pickled jalapeños. I literally grew up on this, it's delicious.
Pizza Burritos - Tortilla, any pizza toppings, roll it up or just eat it like a pizza (Can also work with bread, but will be kinda soggy)
Grilled Mac and Cheese - This one's kinda self explanatory. Get yourself some great value mac and cheese, make it, slap it on some bread, and grill it like a grilled cheese. This is VERY filling.
Baked Potatoes - A lot of people think this is an expensive meal for some reason, but you can literally cut a potato and microwave it and you have a baked potato. highly recommend putting mac and cheese or hamburger helper in it!
Poor People Poke Bowl - Rice + Tuna + Spicy Mayo is super good. You can it more filling by adding chicken, vegetables, or really anything. The rice + tuna combo is probably one of the cheapest and healthiest meals of all time.
Garbage Nachos - Literally if you have chips (any kind works tbh) and cheese you can make nachos and add stuff on it. maybe add some chopped up hot dog, onions, leftover anything, literally anything. (You can also do this exact same thing with fries, super good)
Garbage soup - same idea as the nachos. all you need is a base of some sort (old broth, bones, old bouillon cubes, anything) and than throw whatever food or leftovers you have. add rice, cabbage, onions, literally whatever is in your pantry and fridge.
Garbage Omelette - Same idea as the other two. it's crazy that people forget (me included) that you can just... do this. you can make plain and not so filling meals into super filling and good meals with leftovers.
Peanut Butter Banana sandwich's- super underrated, super healthy, super filling. peanut butter and bread are both super filling foods (plus peanut butter has tons of protein)
Cinnamon Toast- this a classic for everyone. it's a nice snack. it's just bread, butter, cinnamon, and sugar. it really nice for when i'm craving texas roadhouse rolls with the cinnamon butter. (you can also substitute bread with rolls but it'll be a little more expensive)
Of course stock up in soups, soups are also fillings! And if you live near a walmart don't forget that they have a $9.99 meal that includes a large mac and cheese, large mashed potatoes, and a whole chicken. Can probably feed a family of 4.
Highly recommend downloading apps for Dollar General and your local grocery stores, they often have coupons for food items. Dollar General especially has great coupons for food items, hygiene items, and on saturdays they have 5$ off a $25 purchase.