NaNoWriMo is challenging, without doubt. The trick is to push on regardless, to accept that what you are getting into the machine is a rough first draft, not something you'll be punting to an agent or publisher come December first. The NaNoPeeps understand this and they give participants all the help they can, including regular pep talks. I got this one, written by Holly Black, today and I found it extremely useful. Check it out, if you've a mind.
NaNoWriMo word count: 3706