It's an anniversary, of sorts. Two years ago (June of 2011) I decided to quit my job and write. And I have been writing. August 5th will be the next "anniversary," when I officially abandoned my old job and stepped into the dark.
I've learned so much, but the main thing comes down to this. Fear has no part in the decision making process. If you're doing something (or not doing something) because of fear, it's the wrong reason. Every time.
I'm serious. If you're facing someone with a gun and he says get in the car, fear says get in the car. But there are logical reasons NOT to get in that car, not to do as your fear tells you to do. If you want to start your own business but you're afraid you might not succeed, get rid of the fear.
If you're afraid of anything--living your dream, starting a family, changing genres--get the fear out of the way. Easier said than done, but possible. Once you eliminate the fear, the process takes on a life of its own. You can then identify the real reasons why you should or should not do something, and make a decision on that basis.
I tend to get all muddled--fear of taking any action at all. I'm afraid to, I'm afraid not to. I worry about what might happen and what might not happen. I want something and I want the opposite just as much (although for different reasons), which makes it impossible to make a rational decision.
If you're thinking of changing jobs, get rid of the fear. If you want to live your dream, get rid of the fear. Whatever your fear is, push it gently to one side and separate the fear from the decision. Decision making becomes much simpler, and you may just find answers you never expected when you take that first step into the dark.