I am addicted also, but not to the normal Coke..
I only drink Diet Coke, and trust me, it has no sugar at all, i have been lossing weight since last September (i have a normal/strict diet with no more than 150 carbs a day) and i lost more than 15kg since i started.
With normal coke, all my diet would be fucked up, i need more than 1,5L of coke a day, seriously, when i do not have coke to drink, its like i am ten times more hungry and anxious during the entire day.
But, yeah, diet coke is a shit for your body, a lot of people say that in the long term, diet coke is even worst than the normal one (with sugar)