I actually decided to try vaping nicotine to test whether it indeed was a cognition enhancer, and here I am months later addicted like it's nobody's business. Turns out trying this with an addictive personality isn't the greatest idea – appreciate the suggestion though!

Also, the balaclava is interesting: I can imagine the benefit is almost similar to that people get from using a gravity blanket. The weight and "hugging" effect might be very comforting.

Really sorry to hear about the sleep apnea; that's an awful problem to deal with. Hope you're able to find a treatment which works for you.