What is the best way to get over a break-up?

I just went through a break up on January 6, and it was a very romantic and affectionate relationship. The more I think about everything that happen, I feel as if it is my fault, that I am no longer with that person. I am very heart broken, about everything, but I know it is time to move on. What is the best way to do that, and keep composure about everything else?