So what do you do? Read a book, watch a movie, eat a box of vanilla wafers (without the peanut butter, of course), the whole box. Anything but stare into that empty jar.
But eventually you have to confront the lie. You have to look at yourself and say, "That's not true." You have to begin again to speak the truth to yourself. You are a writer because you love to write, you love the words, you love the stories, the sounds, the syntax.
And you open a new file or turn the page in your journal and begin again, because if you don't, you'll be miserable, because you're a writer. Like it or not. That's the truth.