If you find it hard to give up soda, try seltzer water! Please do not confuse this with Club Soda or Ginger Ale. Seltzer water has no calories, no sweetener (sugar or artificial), and no sodium. With this you get your "bubbles" without the sugar and chemicals. Who needs that?
You can get seltzer water in cans. Not all stores carry it but I get mine at Safeway. My family drinks it plain, but if that's not your style, try it with a squeeze of lemon, lime, or a splash of juice. You'll love it!