I believe this was caused by a temporary return of the dysautonomia I had been previously diagnosed with. I figured out what it was after noticing that I had orthostatic hypotension again, and that it was worse after eating/during a light-headed/dizzy spell. Repletion of electrolytes (drank sea salt water) put an end to it, and I'm now 'normal' in that regard.
Re parasites: I stopped passing worms, started to feel better generally, and then muscle tested all of the drugs and parasites. They were all 'weak'/'negative', so it seems I may be parasite free for the time being. I plan on retesting, and taking follow-up and prophylactic doses in the future. I also did a liver flush yesterday and saw no evidence of parasites, just a small bit of yeast that I'll be dealing with immediately.