Breathe. We'll all forgive you if you don't come up with a chapter for a while... I should probably write something for my fics, come to think of it.
You just need to breathe.
I find that rereading old fics that I've previously written helps (often along the lines of "let's never write something like THAT again", but still...), or maybe taking a brief stroll through the badly-done Mary-Sue fics out there. Don't actually read the fics, just the summaries. Then be glad that you aren't those writers.

Mr. Quackie and I wish you luck upon your quest!