Writing is a process and you must trust the process! Fear and anxiety are part of that process along with the enthusaism and the good days and the joy and the passion and the great hopes you have for a book. But when you run into problems, when you get stuck or scared, you must trust that that is part of how a book comes to pass, and what you need to do is get very still and quiet because Self will tell you how to get out of a hole you've dug for yourself.