Self-doubt is the enemy of creativity. Unfortunately, it often goes with the territory. Here's an article that may help.

stop feeling like a failure as a writer Failure hurts, doesn’t it? It can be brutal, humiliating, and demoralizing. From the giddy heights of your initial creative rush, the long hours wrestling to keep your labor of love alive, to landing smack on your face on releasing it into a world that frankly, doesn’t give a damn. That’s one heck of a fall. But we’ve all felt like failures at one point in our lives. And the pain that it brings can be enough for us to slam the brakes on ever trying to be a writer again. However, if you study successful writers, you will discover that one of their most defining characteristics is that they have all failed, sometimes multiple times: failed to finish novels, failed to get them published (assuming they did finish them), failed to make a living writing and even failed to carry on writing. Those writers who succeed understand that to stop feeling like a failure and dare again, you need to re-examine your idea of what failure as a writer actually is and what it means to you. Because before you can start to feel like a successful writer, you must stop feeling like a failed one. Here’s how: 1. Stop seeing failure as your enemy When you fail, you need to know that it isn’t personal. Failure doesn’t wake up eager to single you out as its victim. So stop taking a fail as a personal attack on you and your writing goals. Treating failure as your enemy adds significantly more stress and conflict to the creative process. You need clear thoughts to regroup and re-plan. Don’t waste energy on how battered you feel from the blow of an imaginary adversary. Instead, embrace failure as a friend, as an honest if brutal editor. Friends and editors tell you how things truly are so that you can move on. They’re right there with your best interests at heart. Failure similarly shows you where you need to improve your characterization or plot or strike out on a different approach. […]