A fellow writer agonized over an online interview, certain she'd have nothing of interest to offer, and other writers offered comfort. It highlighted a common problem.
Writers, largely speaking, are ordinary people. It is both our strength and our weakness. It gives us the common insights with our readers that illuminate our writing, but makes it terribly difficult to maintain our self confidence when challenges arise, like interviews, book-signings, personal appearances, etc.
Even a stable of published works with different publishers can't dispel the feelings of being an undiscovered fraud. We revisit them occasionally, anxious for reassurance, only to find every mistake, every piece of sloppy writing, glaring at us from the page. We can only hope our readers are less critical and more forgiving before we go back the solitary hours of writing, beset with the doubts that make us try harder.
I've yet to meet a writer who is complacent about any aspect of their writing at any level except the public face we display to the world. It seems to come with the territory.