The most alarming part was the loss of vocabulary. I was an avid reader and couldn’t call to mind fairly simple multi-syllablic words.
It took 5 years of bumming around in the mountains to heal the damage.
My solution was to say sayonara to everybody and move to Tokyo, to attend a full time Japanese language school, with people generally 10–20 years my juniors. I'm doing good so far, I'm making tons of friends and the school is keeping my mind and my schedule full. (I just picked a random interest and a sufficiently far away place. It could have been cooking or hiking in the Andes, for what matters.)
It's too early to say whether I'm recovering. I hope so. I think I'm seeing some color returning to my hair, but it might just be the light.
For the first 3 years of doing almost nothing productive the progress was quite slow.
In retrospect, a couple of high dose psilocybin sessions may have sped up recovery by reprogramming some of my identity that was at the core of the stress.