It seems that chronic fatigue that comes with chronic illness is very difficult to treat. It’s hard to know if the illness is the cause- autoimmune illnesses definitely are known to cause fatigue- or the treatment.
Even when my autoimmune illness is not active, I’m still tired- just not the extreme exhaustion. I function better and can be somewhat physically active.
I try to read up on chronic fatigue hoping for an easy solution. It doesn’t exist.
Now there is long Covid too- totally different and much still unknown.