I get that, and I had a similar problem when I was first living on my own. I specifically remember deciding to make lasagna from scratch, and when I went to the store to buy the ingredients, it came out to over $50 for one dish (this was probably 10 years ago too, so maybe more like $75 today).
These days I could make a very similar lasagna for about $15, and that would be enough for dinners for entire week or more. It’s definitely not easy, but if you shop around I’m sure you can make it work. There are also a lot of online communities devoted to this very topic. Reddit had r/eatcheaplyandhealthy. Maybe you could start the same community here on Lemmy.
And, even if I do get fast food, Wendy’s is an absolute last resort. I think I’ve only had their food once in the last two decades.