Oh, man. It must be going around or something. I've got something I've been fighting off with only mild success myself. It's an odd combination of things. Haven't had any bad tacos (maybe a torta?), though. It kind of started after I ate Life cereal for the first time in a while. Which is weird. Now, I think it might be a combination of things.
Anyway. I hope you get to feeling better soon.
Keep fighting it then! It was a helluva 24 hours; one I wish never to repeat :) Thank you for the well wishes too ;)