Don't be so hard on yourself Lilli. That is still a heck of a lot of words for one month. I wouldn't think "professional" writers pop out 50k in 30 days on a regular basis anyway. Every year you keep doing more and more, and you beat your all time high. Heck, that's a lot to be proud of. Shows growth as a writer I think.
I'm really struggling with this myself this year, its only the third time I've done it. My 09 story was great, this one just sucks. I tried last year but only got as far as 19k I think.