i hope i am not speaking out of turn, but i did have a similar brain fog. it went away like this:
i got some food grade hydrogen peroxide, 35% at the health food store. this stuff is caustic, so watch out. and make sure you have a good store of B vitamins, coQ10, and alpha lipoic to protect from the oxidizing effects. i did not do this and was fine, but i found out later it was a good idea. i would caution anyone using this stuff to study up! but back to my story.
that evening i put three drops in a tall glass of water and drank it down. i did this on an empty stomach(three hours after food). i got a headache after a bit. not excruciating, just a dull ache, especially frontal. i slept that night in spite of the headache and without aides.
the next morning, the headache was still there. i put four drops in a tall glass of water and drank that. about an hour after that a miracle happened. my lungs opened up and i could breathe twice as deep as before. my headache went away. i felt calm and collected. the fog in my head lifted and i swear, it was like a reverse lobotomy. you can imagine my joy. it was then that i realized that, instead of add and depression, which is what i was diagnosed with and being treated for, that my symptoms had a physical cause and that i could do something about them! i have never been the same since. i have never seen another doctor since. that was about three years ago and i dont supplement much oxygen any more because of the risks and because i am working on total independent health via lifestyle. but boy did that help get me started. after that, i could think well enough to figure the rest out. before that, i couldnt think my way out of a wet paper sack. that is what happened to me.
btw, if you have something on your stomach or take too much of this at one time, you will blow like moby dick! i have seen protocols which have you build up to 40 drops at a time. the operative term being "build up to"! i never got much past 10 drops or so, basically because i was afraid of it and i think i got all i could get out of it. if i had a definite life threatening disease that oxygen would help, i would certainly hit it harder and not be too concerned.