I used to be bad with coke... I would drink about 4-5 cans a day at work. Which is probably worse than drinking Coffee. That's why I cut back to just water, took me a while to get used to it tho... I started getting really bad head aches from not having caffine!
the only time i ever drank coffee was when i worked earlies, when i would go bed at 12 and get up at 4, its only good for keepin you awake, its tastes fuckin dirty, smells dirty and gave me a caffiene-over, a coffee-come-down if ya know what i mean.