I'm glad that you found a way to get past that first daunting challenge! I had the same experience last year. After a few problem moments, I discovered that you don't have to write linearly to get the job done. Now if I have a scene in my head, I write it. I can come back and add it when I get to that point of the story. If I need to modify it to fit it in, I can do that.

With every word you write, that 50,000 goal gets a little less distant. After a few days, the horizon is clearer and clearer! That's what makes NaNoWriMo such an incredible experience.

Good luck and WRITE ON!