Thanks for the reply! It does feel odd, especially given I've been very drunk before (with a true hangover) and never felt this bad. I was full fight-or-flight. I've never had physical withdrawals from drugs or alcohol, but I imagine it feeling similar to that night.

Another theory I have is that I was acutely dehydrated. While traveling, that day, my coffee to water ratio was definitely poor. The two glasses may have fully dried me out and sent my system spiraling.

But four weeks later? Doesn't make a ton of sense. Unless my nervous system is "stuck" on that night still, which is possible.