Have you been diagnosed with MAV? Sorry I haven't seen you other post. I'm new here too.
I have had a lot of "the floating, derealization brain fog feeling" for the last 3 months, among other symptoms, and have just been diagnosed with MAV by Dr S and starting treatment on Pizotifen.
Basically those symptoms are part of the MAV symptom list.
I find Vit b12 (sublingual) tablets, Feverfew, Co Q10 vitamin supplements all help a bit. I take vitamin C as well.
I find being outside in natural light, going for a short walk also helps.
also - de-stress and relax as much as possible. it's hard, but get a meditation app for your phone, do breathing exercises etc, and remember that these are symptoms of a condition - you can manage them to a reasonable extent, but if you overdo it they can get worse. so try to find a balance of what you can manage to do without exacerbating the symptoms.
Let me know if I can help, if you have any more Qs?