I think it took me about 3 days going cold turkey to get past the physical effects of quitting caffeine. But I still miss drinking soda when I take a break from work or exercise. My favorites that I hope to only drink on occasion instead of a couple of times every day: Diet Coke, Coke Zero, and Diet Mountain Dew with a shot of Code Red.
I need to lose some weight, so next up on my to-do list starting tomorrow: log all of my calories with MyFitnessPal. I've had success with it before. Hopefully I will again.