I have tried to break my addiction so many times. Of all the people I've spoken to, those who drink diet Coke have it the worst. I'm always trying to break my addiction to diet coke but I'm never really free of it. I once didn't drink any for a year and I wanted one EVERY DAY.
Even though it's "calorie free" it has a caramel color in it that messes with my blood sugar and the sodium content messes with my BP but I cannot quit drinking it. It's not a caffeine thing. Other caffeinated drinks don't cut it. It's a chemical addiction.
Presently I'm down to ONE 20oz diet Coke a day. If I've done well all day I allow myself one with dinner. The problem is getting myself to replace what I was drinking in DC with water. I just don't drink anything at all.