That sinking feeling

I have calculated that I written 76,025 words of a new novel but have just experienced that sinking feeling that you get when you read your own work back: Oh no, I thought. This is really mediocre. It's nothing like how I imagined it to be (engaging, edgy, interesting, etc). I'm going to have to re-write it. Then re-write it again. Then probably again. And maybe again. Then again. And possibly again. Then maybe I won't get that sinking feeling. At this stage though it is very difficult to tell.