Sometimes you take a job for the money, sometimes you take it for the location, sometimes you take it for the script; there are just a number of reasons, and ultimately what you see is the whole landscape of it. But I can tell you from behind the scenes - that's what it is, as an actor.
I had a good theater career for years. I played Hamlet when I was 22, and I've played some really great roles.
If you want to conquer fear, don't sit home and think about it. Go out and get busy.