I believe artists (including writers) tend to be some of the most insecure people in the world. After all, what we're doing is so much more than just work. We're putting ourselves out there for people to see and--worst of all--criticize.
I don't think I'm alone when I say that I'm very uncertain when I come up with a new story idea or finish another chapter of In the Days. All artists desperately want the approval of others, as that validation proves that they have something they can offer.
Whether it's a new story, a beautiful painting, or a cleverly worded song, there's always a bit of uncertainty when the idea is put out there. The artist has to pull the idea from his or her brain, form it in a way that people can identify with, and then leave it out there for people to examine. People listen to that song, look at the painting, or read the book, and then they go to town with the criticism.
Here's the interesting thing about being on the other side of creation: people who criticize loudest often can do the least.
Think about it…
Most of the greatest art critics in the world are excellent at pointing out the flaws in technique, style, and imagery, but have you seen ANY of their work? The people most vocal about finding mistakes in a manuscript or being annoyed by the repetitive lyrics of a song have never lifted a pen to write anything. They've never put themselves out there, never felt that uncertainty that comes with being a creator.
I ramble, but my point is this: uncertainty is a part of your life as a creator. It is simply your job to continue creating and putting your work out there. People may love it or hate it, but at least it's out there. You got it out of your brain, and you proved--to yourself, at least--that you truly are a creator.
Take that uncertainty, and run with it. Use it to help you constantly strive to improve your work, to always enhance your talents with acquired knowledge. The uncertainty will force you to always try to be better, to do something new, to test the limits of your skill. That, in my opinion, is what makes an artist not just good, but great!