I should have seen it coming: I was writing two books instead of one. Or, how to determine what your story needs

I was about 54,000 words into my manuscript when I could no longer ignore this dreadful, gnawing pit growing in my stomach. Everything was wrong. I wasn’t writing one novel like I had envisioned. I was writing two. Two really bad ones, and I was forcing them into one.

The only thing I was effectively accomplishing was mashing these two halves into a sloppy gruel instead of giving either of them room to cook.

And I should have realized this 20,000 words ago.

So why didn’t I?