Processed food is usually more expensive per portion than the ingredients alone. The farther you get from the raw ingredients the more expensive it gets. Plus, you're eating all sorts of junk ingredients.

I had about ten years of experience with a very tight food budget to learn what was good value for effort/ingredients.

Good:

Flour, sugar, canned tomatoes, spices, frozen veggies, fresh produce

Bad:

Presliced or pre-grated cheeses, at least in my experience, are marked up 1.5x to 2x the cost per pound of a block. Another commenter said that wasn't the case in their store, but check and see if that is true for you and if the cheeses you got are available in blocks. You can even go to a place with a deli counter and they will slice cheese for you for free, and you will get exactly how much you want with less waste (yes it's an interaction with another human, it'll be alright).

Uncrustables/swiss rolls/mac and cheese... it's not for me to judge what someone chooses for an indulgence, maybe those things are what get you through your day, but you can definitely do better value wise. Mac and cheese from a box is cheaper than those individual cups, and homemade mac and cheese from scratch is even better and extremely easy if you have any kitchen experience. Uncrustables will always be more expensive than just making the sandwich yourself. The swiss rolls... well you know they're a treat. In my opinion if you're going to treat yourself to something unhealthy spend the extra dollar and get something luxurious.

Breads and muffins, again if you could learn how to make them yourself you might be impressed with the results. Bread can be a tricky balance of time, effort and cost of ingredients, and homemade fresh baked bread is incredible, but if you're short on time there's nothing wrong with buying it. Muffins are a quick bread though that you could make at home in under an hour with a mixing bowl and a cupcake pan, and then you could control exactly how much sugar went into them and have hot, fresh muffins. It's worth making them yourself at least once to see if it's something you can add to your routine, you can get a cupcake pan for cheap from a thrift store if you don't have one.

Sauces and dips, as other people have said, they are a lot simpler than you might think to make yourself. In my experience they are one of those things you should challenge yourself to make at least once or twice and see how much effort and time it takes you, and then re-evaluate the jarred/canned stuff. Maybe after making it you realize it is worth the extra dollar or so to save yourself the effort, but maybe you realize it's not that hard and you're able to save money in the long run and have more control over the quality and ingredients.

All this stuff is incremental, and any one thing isn't going to magically fix food costs. Plus as the amount of time in your life to spend on meal prep fluctuates you might find it's worth it to spend the extra money on convenience. However it's important to at least get some experience with the alternatives so you understand what amount of time and effort you are buying by getting those processed foods. Good luck :)