My helpful tip is that you may be getting dehydrated. YOu may just be thirsty. Drink water and eat a piece of fruit or a sandwich. Get your energy from something else, not from a fizzy drink. That will be your quickest way to let coke go, i think.
I am a cold turkey kind of person.
It may take you more than one attempt in the long run but i think you should give it a try to ditch all soda and not replace them with something else equally lacking nutrition.