One thing I see a lot in writing advice communities is posts that boil down to “I was writing a book, but now I hate my book. What do I do?” The answer is almost always “write the rest of the book,” but some thoughts on particular varieties of “hating the book,” broken down:
1) “This is my first novel. I wrote the first 10,000 words very fast and very easily, and it was fun! Now everything is terrible and I hate it.” This is developmental – it’s the point where sketching for the book has to turn into actually structuring and writing the book. If you find outlines helpful, write an outline, then write the next thing in your outline. If you’re a pure pantser, figure out what your main character’s main problem is, then have them take some action to try to fix it.
2) “This is my first novel. I have almost finished it, but have had the sudden realization that it is horrible and I should never write again.” This one’s about fear. When you finish the book, it will then exist as a real manuscript with flaws, and won’t be the perfect vision in your head. Unfortunately, no one can publish the book in your head, because it’s imaginary. Put yourself back in front of the keyboard and write an ending. It can be an objectively terrible ending, but when it’s written, then you have a whole book that you can edit, which is easier.
3) “I am three-quarters of the way through the book, right before the climax, and I am now [reorganizing my pantry/knitting my taxes/washing the baseboards] so that I don’t have to work on the book.” I think this one is also usually normal developmental hate. The point right before all the plot threads come together and the book starts rolling downhill to the ending is messy and fiddly and feels hard. There’s no way out but through, although your house may look fabulous by then.
4) “This is NOT my first novel, and I’m partway into the book but not yet near the climax, and suddenly everything feels wrong and I hate what I’m writing.” This is the point at which I’d look most seriously for structural issues. Do you have the right point of view character? Did the plot take a serious wrong turn? Producing negative word count always stings, but consider ripping out back to where you felt like things were working and starting again.*
*I don’t recommend ripping out if you’re writing your first novel. The chances that you have correctly identified what you need to fix and are not just tearing the plane apart while flying it are slim. Instead, if you feel like you need to change something major, I recommend making as few changes as humanly possible to past pages and then carrying on as if you’d already done the rewrite. It’s fine if the first few chapters are in first person and you are going to need to change them to third person. It’s fine if you have notes saying “actually her mother isn’t dead, she’s become a supervillain” and then you just start writing alive!villain!mother as if she’d been there all along. Let messy stuff stay messy. First-time authors are SUPER vulnerable to churn, where you write your first three chapters over and over again instead of writing the rest of the book. Don’t churn. You’ll edit later. Write the rest of the book.