Gardner is correct, marijuana is stored in your fat cells. That's why drinking a lot of water won't flush it out of your system (contrary to popular belief); it just dilutes your urine.
I've known lots of people over the years who smoked pot. Some did it a couple times a year, some all day every day. Some of the "all day" smokers quit when they got jobs, or wives, or whatever. I know a few who have had great difficulty quitting the reefer. Isn't it amazing and frustrating and odd how the exact same substance can have such different reactions on people, even people who seem very similar in character and nature?
Good luck, Gardner. I hope you're able to get some food into your system. I know it's tough when your body is used to eating while you're stoned, then it doesn't want food when you haven't been smoking. Just remember, like all things, that will pass and you'll be able to eat a healthy meal again in no time. Maybe not today, but it'll come. Stay strong.