Okay, here's what happened to me. It sounds somewhat similar to what you all have described.
I usually go to the same Chipotle about twice a month (sometimes more). I *ALWAYS* get a Fajita Burrito with Carnitas (pork). My toppings are always the same.
This past Friday, my friend and I went and my friend went in and ordered. He made a mistake on mine and got the regular burrito (this comes with black beans versus the peppers). This is not a big deal, I've had the beans before and never a problem.
So, as I'm eating the burrito, I notice that the pork is EXTREMELY salty. The burrito was good but the pork was noticeably salty and my friend also noticed it and commented.
As I finished the last bite of the burrito, it honestly felt like a switch clicked off in my head. I had these weird feeling of "doom" come over me. I got very shaky and my heart was racing. I went to my desk and took a few deep breaths, thinking it was some type of panic attack (but it wasn't). The next thing I know, across my shoulders and collarbone, my skin had a sensation of being VERY cold. Yet, when I touched it, it felt normal. It was just a sensation.
I then went to the restroom and my legs were very shaky.
This whole weird panicky episode lasted about an hour. For the rest of Friday evening, my legs felt very shaky and I felt weak. I was extremely tired.
On Saturday morning I awoke with a fairly bad headache which lasted ALL day. I was extremely tired and when I was doing my errands, I felt like every step was an effort with my muscles. I woke up Sunday and felt much better.
I have had a few episodes like this before--all a tad different but very similar. All had to do with eating out somewhere. Once in a Chinese restaurant, once in a Thai restaurant (which claims not to use MSG), once in a restaurant where I had only eaten bread and butter, and then again when I made chicken salad from a rotisserie chicken (that I had eaten the night before with no problem).
Well, thanks for responding. I think I'm on to something.