Need energy!

About a month ago I started working different hours. I wake up at 2am and have to be at work by 3. I'm off work no later than 10:30. Ever since I started working these hours, I have had ZERO energy. I try to take naps occasionally and just wake up more tired than before. Right now I have a cold and I know that's not helping any. But I'm dying to feel fully rested. I just had 2 days off last week and slept a lot buy I'm still drained. Any ideas on how to get some sort of energy because Red Bull isn't doing the trick any more.