Do work at a desk, not your bed. Your bed is where you sleep; your desk is where you work and concentrate. Your mind makes these sorts of associations subconsciously, which means that you're sending a "sleep" signal to your mind if you're trying to work on your bed. This is counterproductive because you're actually asking your brain to do two things at once (concentrate ' sleep). Instead, ask your brain to either concentrate
or sleep by choosing your workstation carefully.