2023? fiction book about Mom grieving her child and making a monster from her child

I’m not sure on the specifics but I believe the book was written in 2023 because I checked it out from a public library in a collection of books that earned a 2023 award (I already checked GoodReads but couldn’t find the title). The book opens with a mother describing her broken relationship with her husband after they are consumed by grief by the death of their child and her ultimately leaving him and possibly taking the body of her child with her. I didn’t get far after that, but from the description I believe she tries to resurrect her child or reincarnate his soul with a part of his body. I also oddly remember there being a description of her husband showering at the beginning of the novel and him growing depressed and not taking care of his body as much. Any help would be appreciated!