It's a long read with a lot of data and can be hard to make sense of. Here is the TLDR:
Conclusion
The interpretation which seems to best resolve everything I know about magnesium with the data from my experiment is that magnesium supplementation does indeed help me a large amount, but I was taking way too much.
The couple paragraphs above this citation are also worth reading, in particular:
I find this very troubling. The magnesium supplementation was harmful enough to do a lot of cumulative damage over the months involved, but not so blatantly harmful enough as to be noticeable without a randomized blind self-experiment or at least systematic data collection—neither of which are common among people who would be supplementing magnesium I would much prefer it if my magnesium overdose had come with visible harm (such as waking up in the middle of the night after a nightmare soaked in sweat), since then I’d know quickly and surely, as would anyone else taking magnesium. But the harm I observed in my data? For all I know, that could be affecting every user of magnesium supplements! How would we know otherwise?
Conclusion
The interpretation which seems to best resolve everything I know about magnesium with the data from my experiment is that magnesium supplementation does indeed help me a large amount, but I was taking way too much.