I drink about half a pot of coffee a day, but it still doesn't make a difference if I am feeling fatigued or manic. I've done a lot of experiments in trying to keep caffeine out of my body, but when I simply CAN'T sleep: I need it or I feel irritably cranky with my inability to rest. If I must be awake, at least I'd like to be able to function. But on top of bipolar, I also have cyclothymia. So sometimes I will be awake for 8 hours & asleep for 14, then awake for 22 & asleep for 9. It's very hard to determine sometimes if it is insomnia or merely my circadian rhythm being off kilter.