I like what
@tinkerdan said about using it to become excellent, but that's not an easy thing, really. I deal with this every time I sit down to write. Every time I start a chapter, every sentence and every scene, and every time I finish something. It is always there. It just comes with the territory. There is always that feeling of self-doubt sneaking its talons into your mind.
Hell, when I share a story and people like it, I wonder, "but did they actually like it, though?"
I've learned to deal with it by accepting that what I write may not be the best thing since sliced bread. That's okay with me. I use it to express emotions and ideas that I wouldn't otherwise do in another way. I tend to keep things to myself, of course. It is always difficult to think about someone reading what I've written. Then the thought that they will have opinions on it, compare it to others, etc.
Hello, self-doubt. Welcome. The usual?
@The Big Peat is right, too. It can lessen as you press on, but it never really goes away. Like he said, having it countered with a little confidence or accomplishment will help push it back a little. Enough to get some damn breathing room.
I still want to be a success, and I would love to quit my job and be able to churn out books the rest of my life. Will I ever get there? I don't know, but I've learned to accept where I am now so that I can continue to work on my craft to hopefully get better.
Peace and acceptance. Those are the two things that have helped me tolerate the whispers in my ear. I hope you can find both as well.