Oooh, never look back at your NaNo novel! Not until December.
I feel your pain, skylessbird. I will say I think of NaNo as the early stages of throwing clay: if you get out of it with a lump of more-or-less novel-sized goop and a vague idea of what you want to sculpt it into, you're in good shape.
One of my favorite writer anecdotes is from Dennis Lehane (
Mystic River and
Gone Baby Gone, among others). I heard him speak a little after his career took off big. He said when would get full of himself, his friends would call him and read sections of his first drafts into his answering machine.
First drafts are often awful because they are first drafts. You can't fix the book in revisions if you don't have a book to begin with.