You can use them to make bread actually. And thicken a soup. Some of my favorite ways to hide them. And that should help disperse whatever is happening with them.
I think you might have a gastro issue with them. Potatoes are so high in basically everything that they can upset your stomach, and it not be a grease thing. Unless you are getting really grean skinned potatoes full of solanine you might actually be best using them sparingly.
You could look into yams. Sweeter but usually still cheap and pretty darn healthy. I would also say grow peas or green beans. They sprout in days and will harvest for month/s.
Unfortunately if you struggle with potatoes you might also struggle with eggplant that also tends to be cheap.
If you have zucchini I love to just cut them in half and scoop out some of the inside center and mix that with breadcrumbs and sauce and some cheese put it back in the zucchini boat and bake them. They store well and are pretty filling.
I get food insecurity. I once had to feed my whole family on the budget of just my paper route because of a drunk Mom. It's not fun. But if you let me know what is cheap around you maybe we can figure out something if you want.