You know when you are burned out and you seek advice from other people?
Brain fog? exercise, magnesium and so on
Can't sleep? drink milk
Tired? Eat well, take vitamins
I did all these and while it did help, it also felt like I was returning $1 on a $1 million debt.
So the wort burnout I've got was due to some stomach bug. This prevented the normal absorption of food and soon enough I was running on fumes (while still being quite active).
What's interesting is that at this point all those advises don't actually solve anything, they might even make things worse.
Brain fog? you don't get any fuel for your brain, so yes brain frog. Do you also exercise or do some treks? Your fuel tank is empty and you force your body to eat into your body to take what it needs. It will make you fell worse, not better. If you exercise and almost immediately feel sleepy, that's a clear sign.
Can't sleep? yes, chronic illness will do that to you. Your body is in a state of panic because it knows that something is very wrong. You don't fall asleep anymore, you just collapse from being awake for too long.
Depressed? all your days start to look a like, chronic illness will do that to you.
Anxious? you drink chamomile tea? will not fix the underlying issue. Nice try.
So you find the actual problem and you fix it. Now you are OK, right? well no. You are missing all the minerals and all the vitamins your body could not absorb. I took some multivitamins and that felt good, some magnesium and I felt only a little better and the last one was Vitamin C. That felt amazing. All the muscle and joint pain, and lack of focus disappeared.
Suddenly I could focus, I could exercise, I could cook for myself, go out and so on. Only from this point forward I can follow those well meaning advises.
Not sure from where I took the bug, my guess is the water. Given that a lot of people don't actually have access to good water I think it's very common. Also a big problem is that you don't actually feel ill. I never had diarrhea for example. It starts very innocent as a mood change and nothing else: you don't quite feel it today, a little hard to focus, you sleep a little worse next day/week/month and now you are even less able to focus, but you blame it on the bad sleep and so on. The things compound and once you are in that hole it's much harder to get out.
So my advice is if you have a bad mood for a long period of time, then you might have something physically wrong with you and look into that. No amount of meditation, tea or anything else, can fix that for you.
Interestingly I had periods in which I felt better. It turns out I was consuming Coca-Cola which has a slight antibacterial effect. But given that I didn't know the root cause at the time, I felt worse when I was trying to live healthy and so I stopped the Coke.