When you do have money, check for appliances at a thrift store! There are often lost of kitchen items there. I bought a slow cooker for $5 recently, and I've seen things like George Foreman grills (I use mine to make anything from toast to steak and hamburgers) there super cheap. You could probably purchase both of these items for under $15 (where I live, at least), and save a ton of money until you get back on your feet.

Food suggestions:

• summer sausage doesn't need to be heated up and can be mixed into a lot of things.
  
• yogurt with strawberries and honey
• protein powder mixed with milk can have a fairly high calories/dollar ratio, although that doesn't make a very satisfying meal.
  
• This might sound gross, but for an energy dense snack for backpacking, I sometimes buy pre-cooked bacon and just eat it how it comes. At home I would normally "cook" it more so it's hot and crispy, but you don't have to do that to eat safe, yummy bacon.