Hi!
I think my book would be "All Our Broken Pieces" by L.D. Crichton.
It is a book about a girl having OCD. I also have OCD so I thought it was a very relatable book, and it was very comforting knowing that I am not alone. There are two main characters, Lennon and Kyler. Lennon has OCD and she feels insecure, and Kyler was in a house fire as a kid and has a scar on his face that he struggles to hide. They both feel insecure about themselves, but they learn to be themselves in each other.
It may not seem like a life-impacting book, but I just really really liked it, and I've sort of been learning to cope with it and be myself.
It is my absolute favorite book of all time!!!