The Lathe of Heaven, by Ursula K. LeGuin. This was serialized in Amazing March & May 1971, and was nominated for both Hugo, Nebula awards. Reality is a dream. George Orr is the dreamer. George's dreams come true - he can change the world. In the hands of a power-mad psychiatrist, George is forced to dream up a new reality, free from war, disease, and overpopulation. But there are terrifying side-effects, and George must dream and dream again, forever seeking utopia, until the fabric of existence must collapse...