I'd definitely suggest getting a job, if you don't already have one. It can be anything really, as long as it pays, that way you can buy your own food, or at least help out with the food costs. And when possible, buy ingrediants for things instead of just buying the heat-and-eat types of meals you can get. Like my fiancee and I make our own pasta sauce from whole canned tomatoes, crushed tomatoes, tomato paste, and spices. I don't have the recipe off the top of my head since we usually just wing it until things start tasting yummy. But it's really cheap. We usually make a big batch that can last us well over a week, if not two or three weeks depending on how many things we make with sauce.
When I'm feeling strapped for money though, I like to look for sale items of things I already buy. Or things similar to what I normally buy. So if I normally buy fresh veggies, I can look for canned or frozen veggies that are similar, but cheaper. The more you do in the kitchen yourself, the cheaper things will be because then you're just paying for the food and not any prep work that the companies have already done for you.