From one of those lists of quotes by famous writers that go around every so often, which usually comprise a smidgeon of generic inspiration with some pat condescension and a whole lot of discouragement (at least that’s how I tend to experience them), here’s one I thought was actually pretty helpful:
Start telling the stories that only you can tell, because there’ll always be better writers than you and there’ll always be smarter writers than you. There will always be people who are much better at doing this or doing that — but you are the only you.
― Neil Gaiman
(Gaiman is, of course, the best-selling fantasy novelist who created The Sandman, one of the most sublime comic-books-for-grownups ever written… just in case you didn’t know… )