One food which is really healthy, filling and inexpensive (I think so at least, I live in Israel so I’m not sure how much it is by you). (and all my kids love it) is Oatmeal. We can eat it every day. You don’t need to eat it with milk; you can cook it with just water + flavors. Or bake the whole oats into granola (I can give you a recipe).
I wish you much hatzlacha in your current matzav and hope the future holds good things for you and your family.