I forgot to add.... yes, give up the diet drinks for a while and focus on the water. A lot of people are very sensitive to artificial sweeteners and it could prevent you from loosing. After the 2 weeks, you can try to add them slowly back in if you want to determine if they will cause you problems or not.

I think I may even be a bit sensitive to granulated Splenda! I now only use Davinci Syrups, which are sweetened with liquid Splenda (NO carbs) and I've noticed more loss than before.