I used to drink a 12 pack or more of Mountain Dew daily for a number of years. Quit cold turkey, and have been off of it for roughly a year now. I never got the caffeine addiction or headaches when coming off of it. I think I was more addicted to the taste than anything. One of my buddies used to drink way less than me, but if he didn't have one by noon he had a horrible headache. I could go days without and not get any headaches.

Either way, I'm way more healthy without that in my life. I lost some weight, while already being skinny, because obviously that is a LOT of calories I was missing, but I tried to make up for most of those calories in real food rather than the liquid. I'm not nearly as outgoing or hyper all the time, but I don't have the mood swings I used to get either. I also seemed to have horrible time going to sleep sometimes, but it seems most of the time I fall right asleep now, even when I'm well rested.

It's best to lay off the caffeine, but if you really can't, make sure to have it early and limit the amount you have and you should be fine.