We regularly have $5 meals. I think you just have to have the right mind-set about it -- you will not be able to have a super-deluxe nice cut of meat with special dipping sauce and multiple gourmet side dishes -- get over it

:D . You have to eat a little more simply, but that also means caloric content may be lower, and I assert there is nothing wrong with getting used to simple food. Also, there are things you need to buy on sale, to stock up -- it might seem expensive at the time, but it greatly reduces your per-meal cost. Some of those things for me are: ground beef, beef roast, pork roast, pork chops, boneless chicken breasts, chicken thighs, cream soups, salad dressing, and frozen veggies.
Tuna Casserole (yeah, not my favorite either, but it serves when the cupboard is getting bare): 2 cans tuna, one can cream soup, a little milk, one box pasta, 1/2 bag frozen peas, one cup shredded cheese. Or make your own white sauce instead of cream soup -- even cheaper. Serve with garlic toast if the plates look a little bare. Works out to about $3 or $4 total.
Egg Salad sandwiches: one carton of eggs is only a dollar, whipped salad dressing (like miracle whip) goes on sale for about $2, serve on toast with carrot sticks on the side.
meatballs in mushroom gravy -- 1.5 pounds of 99cent/lb ground beef, white sauce w/ canned sliced mushrooms (or use cream soup, but not as good) served over egg noodles, rice or potatotes, your choice of cooked from frozen veggies.
Breakfast for supper -- scrambled eggs, sausage links, and pancakes or toast. Serve with orange juice (from concentrate) for the vitamins. Even cheaper -- omelettes! You will use less meat, and you can use leftovers for filling.
Stir-fry -- your choice of veggies, but I usually use carrots and broccoli, and usually less than a pound of meat, sliced from a larger roast cut for another meal. I make my own sauce, it's very cheap and usually only requires soy sauce, sugar, vinegar, and broth that I make from boullion. Serve over white rice -- also very cheap.
Baked chicken thighs w/ roasted veggies (carrots, potatoes and onions).
Sloppy joes w/ iceberg salad.
Homemade chicken strips w/ brussels sprouts and baked potatoes.
Gosh, I think I could come up with more, but you probably don't want to read all of them!