Goals for Cooking

Some of my considerations for food in a fast-paced, high-stress life:
-Cost: I'm going straight from undergrad to graduate school, so I not only don't have any money saved up from working, but also haven't paid off any of my loans yet. Needless to say, I'm dead broke.
-Healthiness: I want to eat correctly, and not just eat ramen every night to save a buck (which I'm tempted to do nonetheless). Ideally, I won't need to take supplemental vitamins because I'll be eating all my nutrients.
-Low-calorie: My weight goal is about 25 pounds lighter than what I currently weigh. I would love to say I can go to the gym 2 hours every day, but that's just not realistic.
-Limited time: I enjoy cooking, but again, I can't spend 2 hours making my own home-brewed stews and sauces and bread and all that. I'm going to have about 20 minutes to cook dinner, max.

Essentially, I want food that is filling, healthy, cheap, quick, and low- or medium-calorie. (Is this even possible??)

Solutions, off the top of my head:
-Buy packaged food in bulk. I have no problem sucking up my ego and shopping at WalMart to save a few dollars. Costco is preferable.
-Learn to estimate what I will actually cook and eat myself, since I'm only cooking for 1. I've found in the past that it takes awhile for me to realize how much of a head of lettuce I'll eat before the lettuce goes bad. So, buy fresh food in smaller amounts.
-On the thread of losing weight and all that good stuff, I need to control my emotional and compulsive eating habits. I eat when I'm bored, hungry, full, thinking of a taste I crave, lonely, feeling fat (yes, I realize how silly that is), tired, reading, working, right after working out, late at night, secretly...so basically, I eat. Eating is how I try to solve problems and that clearly creates more problems for me. So, solution: get therapy in Atlanta to figure out the root of this cycle and how to stop it.
-Actually start working out. Since I'll have a few exercise machines in the basement of my apartment building, that should help, since I usually get the urge to work out late at night when it's too late to go to the gym. Though I won't have time to work out all the time, I think a goal of 4 times a week for about 45 minutes is a good goal. Also, I'm buying a bike in about a month, so that should help motivate me to bike places instead of drive.
-Cook in bulk. This will cut down on my cost and my time cooking during the week.