I was doing the same thing with diet coke. I only drink it now if I'm eating out. At home I switched to seltzer with flavor enhancer, like MiO. I wanted to rid myself of aspartame, though I never noticed a difference in not having it anymore.
I never cared for sugared pop. Too sweet.
I've stopped drinking soda as well. Haven't had one in 6 months. I've switched to flavored sparkling water. I like your idea of the Mio. Never thought of that.

I have thought of giving up coffee, but that will be a little harder to do.