My dad has dementia and I need a book that‘s as sad, frustrated and devastated as I feel

As I said in the title, my dad has dementia and it is progressing rather rapidly. His whole personality has changed and it‘s not really easy at the moment to deal with that. He relies heavily on my mother and me, but in a very demanding and controlling way. To put it simply, he is an asshole to everyone around him, especially those closest to him, which I totally understand, but it is still hard to endure.

So, I am looking for a book, that deals with topics like the grief of loosing someone, while that someone is still sitting next to you, or with the frustration of being a caregiver in a situation, that is not going to improve but rather deteriorate. I don‘t want a light-hearted and optimistic book, that finds a bright side in every shitty situation – I want something, that‘s brutal, devastating and horribly sad. It doesn‘t have to feature dementia per se, just similar emotional circumstances.

I‘d prefer fiction over non-fiction and I am usually reading literary fiction, fantasy and classics, but am not really bound to any particular genre.