I can't imagine so many problems stemming just from stress
When my brother landed in hospital and we didn't even know if he's going to make it, let alone come out without being mentally impaired, it took a massive toll on me. Already lost a brother when I was seven, and the fact I now could process more information made it worse. I was oscillating between extreme emotions, under and overeating, no sleep or crashing from exhaustion etc. It didn't end even when he came out of tumour extraction and continued for a few more months.
It didn't impair my ability to think or remember (I'd even argue stress triggers better recall in me, although that might be biased bullshit), but there's a picture of us where most people would mistakenly pick me as the one on chemo.
I'm happy you went to a neurologist and that your nerves are, if not calmed, then at least put mildly at ease. Be responsible and keep on being awesome, man!