uncertainty

I'm reaching this point in my life where I have to make some choices. I mean, life is always full of choices, but at this point the choices I make will probably significantly affect my life. (Side note, I'm having a really hard time typing the word choices.)
It's hard because I'm not 100% positive that I know what I'm doing with my life. I realize that I probably will never be completely sure that I know what I'm doing and I probably just need to pick something and work hard and it will all be fine. Or it won't. In which case I will just make some changes. Anyway, I rarely make decisions without thoroughly contemplating the outcome. I don't go into things unless I am sure (or at least fairly certain) I know the outcome. I hate the unknown, so I avoid it. Unfortunately, I can't really avoid it in this circumstance. And it scares the crap out of me.
So, should I do what makes the most sense financially and practically and will eventually lead to the result I want? Or should I do what sounds more interesting (and makes more sense emotionally) but costs a lot more? I'm in a battle with myself. My logical side is fighting with my emotional side. And I don't know what to do. I really want some magical solution to appear out of the sky. But I've heard that the world doesn't work that way.
It's so strange. I'm absolutely certain that I want to be an adult and I want to act like an adult and be treated like an adult. But I'm also terrified and would like very much to go back and be a child forever. I don't really want that either, though. I guess I don't really know what I want. Again, it's the whole fear of uncertainty.