surviving career transition

For years it's been the same routine -- spend 50-60 hours a week at work and then another 10 hours thinking about how you hate your work. Everyday you ask yourself, "Why did I choose this career?"
Like many people unhappy in their careers, your answer probably falls into one of three categories:1. You chose the same career path as one or both of your parents.
2. Someone told you that you were good at X (i.e. math), therefore you should become Y (i.e., engineer or accountant).
3. You were undecided in the university, so you selected a degree that appeared somewhat interesting.
Let's face it, career change is one of the most difficult challenges you will encounter during your lifetime. Your problem is complex -- you dislike what you do, you don't know what you want to do, you'll crash and burn if something doesn't change, and yet you are paralyzed by fear of the unknown and continue to stagnate.