Hi!! I'm here to recommend this book: "All That's Left in the World." by Erik J. Brown.
It's a story about two boys in a world in ruins post-pandemic.
You'll meet the protagonists: one sarcastic, and the other one strong and sensitive, who remind me a lot of the Billy and Teddy.
"Perhaps it was the scorching heat or my youthful romanticization of Ophelia from my days as a tormented romantic child. But I didn't hesitate before stepping into that enchanting pond."