Books about life struggles, melancholy feelings

Hey!

I have a huge thing for books that talk about ending relationships, sadness, family struggles, etc.

One example is The Light We Lost written by Jill Santopolo. It's not my favorite book, but I like how you can almost feel the protagonist sadness throughout the story.

It's not really easy to find good, deep and emotional books about these find of subjects, so I'd be pleased to receive some recs!