The trick is to soldier on through the novel at this point, though that's easier said than done. If I can say one thing about NaNoWriMo, it's that trying to write 50,000 words in one month really doesn't give me the leisure time required to indulge in my own angst. Instead, I have to suck it up, leave the junky parts as they are, and keep on going with my novel--and this is a wonderful thing. For the other eleven months of the year, when I am not engaged in NaNoWriMo, I often give up and walk away from my manuscript at this stage, sometimes for months or even years at a time.
See, really, all the fun in writing is in the beginning in the end. When you first start, you're so flush with wonderful ideas and so convinced that you have such an exciting concept that you dive right in, sure you're going to produce something marvelous. When you do slog your way past the middle part and make it to the end, you get the pleasure of writing your exciting conclusion and of tying all those plot threads together.
The middle is the real challenge, but NaNoWriMo has helped me to see that the middle is for the editing process. If my scene is boring, I can take an axe to it later and spare my readers the unpleasant experience of having to bear with it. In the past, I used to write as if the words that were coming from me needed to be the end result, but NaNoWriMo has shown me that writing is like any other art. You start out with a rough form and then go back and polish and polish until it's shiny and beautiful. So thank you, NaNoWriMo, for showing me that the sin isn't in writing something that's not good and then deleting it later, the sin is in writing nothing at all.