Don't feel like a failure! The first step is just tracking what you're putting in your mouth, and you are doing that. On the days where I go over, I just say "well, that day is over" and then try to eat light the next day. Maybe it would be helpful for you to go to the store and get some things that you do know how to make to keep on hand?
But, what's stopping you from learning how to cook? I starting learning when I was 25 just by watching the Food Network and now I'm a pretty proficient home cook and cook almost every night. Most of the "instructional" shows are on Saturday mornings. I learned the most from a show called "How to Boil Water" but unfortunately it is not on anymore. They do have a cookbook though: http://www.amazon.com/Boil-Water-Food-Netw
There are also tons of cookbooks w/ recipes for beginners, even the library has cookbooks available. I've not read this one but I've heard it's great for beginners: http://www.amazon.com/The-Dont-Know-Cook-B
I bet your parents would be impressed if you cooked them a healthy meal!