Books about loneliness or finding community / belonging? Fiction or non!

I’m a first year literature PhD student so I want to slowly start thinking about my list of books for comp exams. I’m really interested in subcultures, community, belonging, and the cessation of loneliness, people finding each other, so I would appreciate anything you could recommend to me that fits within that! Classic or contemporary fiction, memoir, nonfiction, graphic novels, theory, sociology, etc. all welcome. 🙂