I've been battling with brain fog and balance for 3 years and high cortisol levels for at least a year. After changing my sleep cycles to night time, exercising and whole foods and recently a low carb and high fat, I think I have turned the corner. The body is very complex, and problems often manifest in other areas. I think high stress over many years has given me leaky gut. Food goes through my stomach wall and into my blood and my body tries to react to it. Something like a form of inflammation, that then raises my cortisol which puts me in a flight flight mode and then my hormone balances are all over the place and my brain shuts down. It has been so bad at times I felt like I was going to die.

I have done a ton of reading on this but Dr Terry Wahls on MS on youtube is a good start.

For all health conditions, healthy eating like we evolved to eat 20000 years ago, ie natural foods, exercise, fasting and a proper sleep pattern with give you the best fighting chance. Especially true about the brain and stomach repair.

Keep a diary and see if you can notice any changes each day. Mine was actually a 3-4 day cycle but carbs was my problem.