In order to finish a manuscript so that it may become a book, writers have to push forward. Write, write, write until you get to the end and then you'll edit later. But it doesn't always work that way. Sometimes, you have to go back before you can go forward. And that's not always a bad thing to do for your books.
To the Drawing Board
There are times when authors have to push. You have to force the words to come. But there are times when the words should flow well, when it comes easily. And if you're not getting to that point, you're going to have to go back. You have to find out what's keeping you from moving forward.
That's what happened to me. I was completely excited about the story I was writing, but every time I tried to write it I just couldn't make the words come. I tried pushing myself. I tried skipping ahead. And then I realized the story didn't want to be told. Not the way I was telling it, anyway.
I had to go back. I took another look at my outline and figured out what was bothering me. The plot just wasn't right, so I had to rework it and re-write the stuff that wasn't working at all. It took a lot of time, but it's worth it to tell the story the right way.
When you just can't move forward with a story, go back and re-work it. Sometimes, that's the best possible thing you can do for the story you need to tell.