This happens to authors all the time: they approach the tail end of a writing project and then find themselves lacking the energy and inspiration to actually finish the book.
Here are 2 ways to get over that:
1. Go back to the beginning of the manuscript, and just read.
It may seem surprising, but try going back to the beginning of your book and just read it. Don’t fix anything. Don’t think. Just read. It may spark the motivation back into you to finish the rest.
2. Remind yourself of why you started.
Think about how great you will feel when you hold the finished book in your hand. Feel the covers between your hands. The pages between your fingers. Think about how proud your family and others will be of you. Don’t quit now.