I echo your 2nd para @Mazarita. Also, big question for me, is the possibility (suggested by some family members) that when I attempted S in 1998 and actually died and was brought back medically, that I was left with residual brain damage. That's a doozy. With that question combined with the way I function as per your last para, I really struggle to have confidence in my brain. And this is coming from one who got HDs at uni in the sciences.
Mum says that before then I could do at least 3 things at once and since then I'm pushing it to attempt 2. My answer to that is that in order to practice mindfulness, one should do 1 thing at a time and be truly present with it, in the now and losing a sense of time. I'm not quite there yet but it is a goal of mine.