Interesting, were you eating healthy as well?
Obviously, you weren't sleeping enough and I'm guessing you weren't regularly drinking enough water as well as the red bulls.
I start work at 5am as well and drink enough coffee to kill a cat, however much that is. I go through stages of drinking energy drinks and I'm off them at the moment but when I do I can drink 4-6 a day. I have noticed they make me feel very edgy and sketchy.
Now I mostly drink water and powerade, coffee aside.
Getting up just after 4am weekdays I find I need to be asleep by 10.30 to feel recharged enough to function properly, 7-8 hrs is ideal for me though.
And yes, Hank Moody is the coolest motherfucker in town.