Warning: the following recommendation may cause existential dread, but it might just lead you to a new favorite book.
For you, we have:
A heartwarming tale of a young adult who discovers that everything they thought was real is, in fact, a lie, and they're stuck in some kind of existential nightmare.
Buy it now, if you dare: /subpages/reading-advice/buy-the-handmade-book-of-infinite-sadness