I can't remember if I wrote this before

, but I found amantadine really helped brain fog. I tried it twice, loved it, but decided to stop because it made it hard for me to sleep. But it doesn't seem to do that to everybody. It is an old anti-viral that works at the dopamine level. Gets prescribed to kids too, and has been around since the 60s.
I may give it another go soon. Good luck!