Why can't you write 'teraz' at the end of the sentence?
It puts not natural accent on "teraz".
This accent can make sense: "Nie chcę czytać teraz." – "I don't want to read NOW, but later."
Why not "Nie chcę teraz przeczytać?"
Perfective "przeczytać" means that you will finish reading it, and therefore it cannot exist without mentioning the thing that you're supposed to read.