Fiction Novels About Death/Loss or with an Autistic Character

I'm looking for fiction novel recommendations for either category (not both in the same book):

Death/loss; some favorites on the topic so far have been Zero K and White Noise by Don DeLillo and On the Beach by Nevil Shute.

Autistic Character; I can't point to any I've read in this category, but I'm not looking for a book about autism, but rather a worthwhile fiction novel about whatever, that happens to have or be from the perspective of an autistic or likely autistic character. I mostly read sci-fi, dystopian, satire, and horror but open to anything on this category.