Just a thought, Jenny - is it possible you were exposed to any unusual/new-to-you chemical prior to the onset of the paralysis, eg paint, pesticide, anything in new furnishings or carpet, etc?
Apart from the 'ME-crash'-related type of paralysis, I did experience a different kind of temporary, partial paralysis at what my ME-diagnosing doctor agreed was likely to have been my original onset in early 1967- got up one morning to find I couldn't lift my feet off the ground to walk, let alone cycle to school (I was supposed to be starting at my new school that day.) It felt like large concrete blocks were attached to my feet. Something in my brain felt odd/wrong.
No-one believed me, parents laughed and called it a silly fuss/ 'first day of school nerves', though I'd been looking forward to it so much, having already made friends there, and hadn't actually been very nervous at all. I did somehow make it to school, just (I eventually managed to persuade my father to take me in the car). In a weak and woozy, exhausted daze all that day, and for months afterwards, with multiple ME-like and OI symptoms, lessening a bit over time. I just covered them all up as best I could, since I didn't think anyone would ever believe me, and got on with my life, albeit in a somewhat reduced fashion. I had no idea what was wrong with me, and hoped by ignoring it, it would somehow cease to exist...
Anyway, skip forward to 1995 when I became too ill/dysfunctional to keep this weird secret affliction hidden any longer, from myself anyway. Gradually came out of denial, started doing the detective work, trying to remember when/how the symptoms had originally started, and recalled that when we moved to that new home, my parents had had an enormous expanse of new carpet installed, that covered the floors of the 2 large main downstairs rooms in our house. It stank, and I could hardly bear to be in the room with it; it made me feel woozy, but I didn't have much choice. The carpet had what the salesman told them was the latest wonderful new innovation - it was impregnated with pesticide - 'to protect it from moth damage'... given the time period, likely to have been DDT, which was madly fashionable at the time. After just a few weeks in the new house, I woke with those paralysing symptoms...
Later that same year, my elder sister came home from University for the holidays. Within a week or so of being in that house, she'd taken to her bed with something seemingly like what I'd been experiencing, but hers was taken seriously, and was diagnosed by a GP as Glandular Fever.
(I was eventually diagnosed with ME/CFS in 1996, my sister in 2001.)
So sorry about the over-long story, and for the speculative nature of much of it; maybe some of it could be relevant to you and maybe none, but I thought I'd just put it out there for you to judge. Oh, yes, and I wondered whether your stiff/sore neck could've been caused by swollen glands, in response to some related chemical or viral etc assault. It's possible my sister's original 'GF' diagnosis may have been simply due to her having swollen glands that were actually in response to the pesticide, or something else. I realise they surely would have checked all that sort of basic stuff for you at the hospital or doctor's, and/or I may have missed something you already said; my apologies if so; I didn't have the mental energy to read the whole thread...