N-acetyl Cysteine and other blood glutamate scavengers (BGS) like malic acid and pyruvate are indispensable in these scenarios. They don't solve the issue but dampen it a bit.
Additionally, a ketogenic diet helped me a lot.
Most of all, high dose niacinamide holds it in remission at times, though I have a theory it's caused by a well-set-in, chronic infection as the reduction in symptoms with niacinamide correlates with the symptoms of fighting off an infection (very swollen lymph nodes, histamine release, sometimes nausea &etc, headaches, some other clear indicators, etc). I've been on it for about 7-8 weeks or so and we're still going!
That said, having energy is a gift that is hard to quantify. Chronic fatigue takes away your ability to think about anything, so you have to have discipline to not think about anything sometimes...which also takes mental energy. It's a bit of a living hell, for suresies.
Here's hoping I get to stay in remission. <3 :')))))
One thing I learned is to ignore figuring out the exact supplements, because you’re playing an impossible balancing game with poor feedback mechanisms. There’s too many inputs.
What helped me was a combination (no one thing can solve it) of therapy (being able to listen to and not suppress emotions), key supplements (magnesium/iron - check out lactoferrin and anaemia of chronic infection), exceptional oral hygiene to reduce inflammation (4 minutes per brush), exceptional gut health (many viruses cause problems with the gut), exercise (eventually), and more…
I never used niacinamide or any of the supplements you used, which shows you that there’s no single approach. I agree that it appears to correlate with an unaddressed infection.
I've also fought a similar battle to you in a similar manner by "fix everything according to best practices."
When it comes to supplements and nutrition, it may be an impossible game, but what's important in finding the right approach is understanding at least the basic mechanism of action and knowing what you're targeting.
What I'm hearing you say is that you had an app with a performance issue, and you couldn't pinpoint whether it was CPU, Memory, Disk, Network, etc, so you solved it by doing a wholesale system upgrade by giving it all the basics that modern science says are the typical health best practices. Magnesium/Iron, exercise, gut biome, oral hygiene, etc to help. All the things you've listed are anti-inflammatory (of course there's other benefits) but generally, anti-inflammatory things are pretty good at making the body run better.
NAC on the other hand, is a precursor to glutathione, a significant anti-inflammatory molecule in the body, and usually the limiting reagent for glutathione synthesis. So it's also arguable that NAC had an anti-inflammatory effect on the body similar to the effects you received from your regimen.
Finding the right supplements are possible for sure. Usually what is needed though is a thorough analysis/observation of someone's diet and then working back the potential malnourishments that are most likely to occur and in alignment with the symptoms. But usually this takes months and years of learning and understanding to even know where to begin when it comes to suggesting a supplement.
To be clear, I found it wasn't a good use of time to spend years experimenting with many supplements that end up working temporarily and then having an antagonist effect on something else that appears months down the line.
The best use of time was taking a holistic approach. Supplements didn't save me - but without some basic supplements I wouldn't have been saved. And I agree, some basis in nutrition is important.