All you've proven is that soda is bad for YOU, specifically, to drink every day. Beyond that you have nothing. 1) you don't have a large sample size of test subjects, 2) you didn't perform any other experiments with, say, gatorade or tea or beer or any other drink you may not drink a lot, 3) You can technically drink any liquid, including poisonous ones, so your claim of it being the "worst thing you can drink" is already illegitimate.
This is just bad science; like, "Super-size Me"-level science (aka, piss poor). I'm not about to claim soda is good for you or even that it isn't bad, but everyone is different and has different levels of tolerances. I USED to drink soda every day as a kid, and I was a skinny kid. These past few years, I generally only drank soda once or twice a week, yet I've GAINED weight. Soda was keeping me thin! I knew it!