Since I found this forum, I've been devouring everything and anything. I mean like 5 hours a day. Now I've noticed a setback. Less energy. More brain fog. Even my stomach has been hurting more. Any familiar stories?
I do feel your pain. Perhaps the brain fog/stomach pain is simply your body saying you've overexerted and need to rest.
My initial post exertional crash onset indicator is a sore throat. Whenever I get a sore throat, I cancel any plans and simply rest. The other symptoms follow a few hours later.
I too wish I had the capacity maintain mental focus. There is so much more I'd like to research on this website. But the brain fog has been relentless the past 2 years.
My neurologist administered some cognitive testing a couple weeks ago. After the one hour test, I spent the next 2 days bedridden.
Personally,
payback for mental exertion is significantly higher than for physical exertion. I'm "lucky" to be just moderate ME/CFS: mostly housebound, but able to do light chores and occasional grocery shopping.
Taking stimulants (Vyvanse) does allow brain to function for a few hours, but generally with days of payback. Been there, done that. Taking daily stimulants is a living hell.
To be unable to use a brain is so unbelievably frustrating. Distracting myself from boredom without triggering PEM is a daily challenge.