Fear of Failure

I went on a rampage last year and wrote four novels. Now that they've been contracted, I'm finally working on a new novel. But, the process is painful, tortorously so. I'm so worried that now that I've published, everything else I create will never measure up. Even so, I force myself to write at least one page a day, but it's like trying to squeeze blood from a turnip, to use a shopworn line.

Any of you other pubbed authors feel that way?