Don't be like me. As a hobby, I started making a music album some time around year 2003. During the next four years I accumulated several hundreds drafts and 16 nearly finished tracks, that only needed the final polish. Then I got stuck. I never did finish one single track.

I was stuck like that for almost ten years. It wasn't until 2016 that I decided to cut the finished tracks down to 7 and publish them as they were, just to close the book and get it out of my system.

I stopped doing music for some years and all the old drafts are archived on old hard drives somewhere in the basement. All I have to show is the published album. The ideas still exists in my head, and maybe I can use some of those, but I don't think any of the material is worth resurrecting to work on.

I finally feel free to start a new project. As a matter of fact, I just did that two weeks ago and finished the first track within the same week, of which the majority happened in a single night. Sure, there are things I think I could improve, but I have decided not to attempt it. It's done as it is. It's more important to move forward than to attempt to perfect something that can never be perfect.

Imagine if you actually managed to write the perfect ending. How the hell would you ever be able to write another book?

My advice would be to write two endings. Pick the least awful one and then publish it, so you can clear your head and start a new book.