First of all, if you are going to put yourself thru this, you need to know that you cannot survive on vitamins alone. You most likely passed out because you are dehydrated and your body needs nutrients. The field trip probably wore your body out to the point of exhaustion. If you insist on living this way, and you can control yourself to not eat for several days at a time, then you should have the self control to at least have a nutrient bar of some type or a protein shake at the very least once a day. You should be careful purging the stomach acid, because when you get older and you are getting older every day - the acid from your stomach will start to each away at the enamel of your teeth and you will end up looking like a meth adict if you can't afford the dental work. Be careful. I should be telling you to stop this, but I know better and I know that you are going to do what you want to do. Don't over do the vitamins, your body only stores the amount it needs anyway and the rest is a waste...get out those science, biology and other books and research this.