I sort of quit caffeine a few weeks ago. I got poisoned, couldn't eat for a few days and then only really bland stuff for like a week, and when that was over I was like, well damn I haven't drank caffeine for over a week let me try to keep it that way. It's getting hard though, don't know if I'll keep it up.
Good luck with your caffeine-free life. I've quit caffeine loads of times before too and there is a hard period with stamina for sometime after but eventually your body should course correct itself with that.