If you are not enjoying your book, you are free to close it and never open it again. Even if it’s a classic that everyone loved. A book has one job, it literally only has to be interesting. If it’s not, have no guilt about not finishing it.
In Romanian we say “library mouse” (șoarece de bibliotecă) when we refer to bookworms and I think this is one of the sweetest things ever because every single time when I like someone who reads, I start to call them “little mouse” (șoricel) and they get instantly an adorable aura.
Books don’t necessarily cure sadness but they are dependable and consoling. They don’t zap away the problems in your life but they take you into another world where your problems become so much lighter. I really think I’d go mad without books.