Wrapping up a story is difficult. You have so many threads and they all must come together in the end. There are so many characters, and they all need an acceptable outcome. Everything has been working towards the climax and it is finally here.
There is a level of sadness to finishing a work. The characters you have come to know and love will not be seen again… or at least not for some time. When written well, they become people you know, and there is a feeling of loss when you realize they will take their place on the shelf.
Also, there is anxiety, because the story will be judged by its ending. No matter what came before, if the reader is unsatisfied with the end, it sours them concerning the entire book. But you have been building to this point all along. So, hopefully, you are prepared.
In the completion of a work, there is a balance which must be achieved between expectations and reality. What the audience wants may not be best for the story. But be mindful to give them what they need.
It is a good idea to tie up the loose ends, as well. Not to do so, leaves too many questions in the reader’s mind. Just as in a garment, people will tolerate a loose thread here or there. But if there are too many, they think about returning the merchandise.