There's nothing wrong with having copies of your book in both languages--try reading them in tandem. Also, think about this as a different kind of reading until you get proficient. It's more fun if you take plenty of time, read passages out loud, make flashcards, etc. Popular fiction includes quite a lot of vernacular and slang that you might not find easily in language instruction materials. When you layer on the author's style and use of literary devices, that's quite a lot of complexity to understand in one read-through. Good for you, OP for branching out in a new language!!