A man once complained bitterly to R' Levi Yitzchok of Berditchev that his business was failing. He was completely absorbed with this and could not think of anything else. His life had come to a standstill.
R' Levi Yitzchok said, 'You cannot think of anything else? Come, let us go to the mikveh." The man assumed that R' Levi Yitzchok intended to enhance his prayers for him by purifying himself in the mikveh. Once they were in the mikveh, R' Levi Yitzchok submerged the man's head underwater, and the man struggled to break free. R' Levi Yitzchok then said, "What was in your mind when I held your head under water?" "I wanted to breathe," the man said. "Were you thinking about your business?" "No," the man said, "I just wanted to be able to breathe."
"Then there is something more important to you than your business, isn't there? You should think of all the other things that are actually more important than your business and direct proper attention to them. Then you will act more constructively, and a more positive attitude will help you in your business as well."
Taken from 'The Enemy Within' by Rabbi Abraham J. Twerski.