I Need An Energy Boost

Right now I am dealing with another back injury and nerve root inflammation. Just walking is exhausting as I have to think about every step. I'm also having trouble sleeping and am in almost constant pain. What can I eat, drink or take to provide more energy? I'm trying to continue to work but can hardly make it through the day. I confess I've resorted to my old habit of Dr. Pepper, but all that Sugar is not good when dealing with inflammation. I've tried fruit juices and whole fruits but I need a bit more punch. Please-any suggestions that are safe, natural and healthy?