It's a good thing to let our thoughts turn to God and His love for us before we go to sleep, so I don't want to discourage you from praying and reading your Bible then (at least briefly). The Psalmist said of God, "On my bed I remember you; I think of you through the watches of the night" (Psalm 63:6).
But what I would strongly urge you to do is to set aside a time during the day when you are alert and you won't be interrupted, and read your Bible and pray then. Why should we leave our time with God until the end of the day when we're too tired to concentrate? God deserves our best–including the best minutes of our day.
Perhaps you feel you are too busy during the day–but are you too busy to eat? You see, we make time for things we believe are important–and that is what I'm urging you to do. Is anything more important to you than your relationship with God? Make time for God, even if it is only a few minutes at first. You need Him–and He wants your fellowship. No one was busier than Jesus–and yet He gave priority to His time alone with His Father. The Bible says, "Very early in the morning, while it was still dark, Jesus got up, left the house and went off to a solitary place, where he prayed" (Mark 1:35). God will bless you as you spend time with Him every day.