Im sorry if true man. Im not sure there's anything anyone here can say to make you feel better. Most people here enjoy trashing people when they are down so here is not the place to get counselling. All I can say is tomorrow is a new day and it will come. Life goes on. You will be better and stronger from this. There are plenty of fish in the sea. Maybe you only thought she was the one because you were so comfortable (being with her for 3 years) you didnt realize how you guys weren't meant to be. Maybe you find someone much better for you because of this. Unfortunately (or fortunately), you cannot control all the happenings in your life. The difference between those who find true happiness and those who don't is their belief that it will all work out for the best in the end.
Take Steve Jobs for example. He was forced to drop out of college because of money. He ended up floating around in classes after he dropped out. As the result of one of the classes he never would have taken had he stayed in school he was able to start building a very successful business. If he had not dropped out of college, Apple would not be a company today.