Any non-fiction books that deal with childhood grief from a non-religious perspective?

I lost my father at fifteen and I am turning eighteen in two months. In the almost three years without him, I’ve found religious comfort harder and harder to find solace in as my loss pushed me away from my religion completely, and I am now atheist.

I am looking for a book that talks about losing a parent (or immediate family member) at a young age that views grief from a non-religious/spiritual perspective, but still has a way of looking at loss with some sense of comfort.

Preferably non-fiction as I struggle to read fiction books unless they are comics because I can’t understand characters’ intentions through writing.

Thanks!