I am at THAT part of the book. Neil Gaiman wrote about it for NaNo 2007, part of his pep talk.
By now you're probably ready to give up. You're past that first fine furious rapture when every character and idea is new and entertaining. You're not yet at the momentous downhill slide to the end, when words and images tumble out of your head sometimes faster than you can get them down on paper. You're in the middle, a little past the half-way point. The glamour has faded, the magic has gone, your back hurts from all the typing, your family, friends and random email acquaintances have gone from being encouraging or at least accepting to now complaining that they never see you any more---and that even when they do you're preoccupied and no fun. You don't know why you started your novel, you no longer remember why you imagined that anyone would want to read it, and you're pretty sure that even if you finish it it won't have been worth the time or energy and every time you stop long enough to compare it to the thing that you had in your head when you began---a glittering, brilliant, wonderful novel, in which every word spits fire and burns, a book as good or better than the best book you ever read---it falls so painfully short that you're pretty sure that it would be a mercy simply to delete the whole thing.
Yep, that's the part I'm at. He goes on to tell a story about how in the middle of "Anasi Boys" he called his agent to tell her that the book sucked, the characters sucked, the story sucked, the plot sucked, he sucked, and he was going to quit writing this book to start another that someone might want to read or possibly to be a bricklayer. His agent responded, "Oh, you're at that part of the book." Apparently, he does this on every book, he just hadn't realized it until then. So, his agent told him, did every other client she has.
So I'm not giving up. Even though my book sucks, the characters suck, the story sucks, the plot sucks, and I suck. I figured I probably wasn't the only person to hit this wall, and since I have Gaiman's pep talk linked as a favorite for when I need the pep, I should pass it on.