I’m approaching the end of my novel in my big re-read. To put it simply, it is so. Hard.
The ending is always the most difficult part of writing a story, I think. There is no more possibility of a great story, not the amorphous, semi-imaginary one that you’ve conceived in your head, anyway.
It is now real, out of your head and on the page. It may not be right, some people may not like it. And, you’re probably going to end up rewriting a whole bunch of stuff anyway, which very may well include the ending.