After quitting soda, I can't even bring myself to drink the zero cal stuff. Artificial sweeteners make me feel cruddy too. At the bar I'm more likely to opt for an ultra light beer over a diet soda now. I vote flavored seltzer water- maybe with a bit of stevia/xylitol/erythritol if you need a little sweet.
OR check out Zevia soda. www.zevia.com Natural zero cal soda. It's not bad, but horribly sweet if you're not used to sweet stuff.