It's nothing to be ashamed of. There's a friend of mine - an excellent writer, by the way, much more respected in pokemon fandom than I am - who could never even dream of doing NaNo, 'cause she writes too freaking slowly.

Maybe you need inspiration. Some people can sit down and force themselves to write (like me!) others can only really do it when the mood hits them and they get an idea. Maybe writing isn't your medium. NaNo's great if it works, and I would've liked it to work for you (both as a confidence booster and because I'd like to read your stuff) but if it doesn't it doesn't.