It happens to me. It happens to pretty much everyone I know. Any writers who DO NOT go through this…they keep quiet about it.
Many people labor under the illusion that, for some reason, all your writing should be awesome right away or you should give up. Nothing could be further from the truth.
The trick to finishing a book? Is finishing it.
The trick to getting through the middle? Is working through to the end.
The trick to pushing past that point? Is to abandon ALL FEAR of being bad. Wrap your arms around the idea of being bad.
MOST THINGS are bad when you are first learning or doing them.
DARE TO SUCK at it. The world will not explode if your draft is bad. Or even if the book is bad when it’s totally rewritten and done. You need to be really bad for a long time, so GET COMFORTABLE WITH IT. Seriously. Not a word of a joke or a lie.
Think about it. If you were, say, playing the violin, would you expect to pick it up and INSTANTLY BE GREAT AT IT? No. You will suck at it until you learn how to do it, and you learn how to do it by sucking at it for a long time and practicing. The same with sports, and dancing, and other instruments, and really many, many things in life.
Many people who are FAMOUS FOR WRITING write terrible things EVERY DAY. They do not worry. Writing a thing badly is often a critical step on the path to writing it well.
If you give up, it does not get finished.
So do not give up. Keep going, even through fear and the annoyance and the boredom and the blocks and the crisis of talent and all of those things. They are ghosts in the mist. Just walk right through them. It sounds both hard and simple, I know, but that is the way.