I think the best thing to quote is, “You’re your own worst critic.”
I believe almost every author has a time in which they look at what they write and rip it to pieces. It could be a want for perfection, or a consideration that your own skills aren’t good enough. The best thing I can say to you is that you’re human. Writing is ever-developing, and quality is perceptive to the individual.
I would say write something that you enjoy, and share it. See what others think of your work, and improve it based on an outside critique. Enjoy what you write. You won’t get very far in your writing if the only thing giving you feedback is yourself. You know what you want to write, so you know the holes in your writing, but that doesn’t mean you know how to fix them. Other people are a good way to find those fixes, as well as learn more regarding your writing.