NeuroTalk Support Groups - unknown diagnosis, a bit scared

Hi, I'm new here, and new to these problems.

3 weeks ago I went into hospital with pneumonia. Within 2 days, my legs/groin area were paralysed, and I had numbness and tingling up to my stomach. Thanks to physiotherapy, 2 weeks later I was able to start walking again, although my balance isn't good and I had muscle wasting in my legs, so I'm still weak and easily tired. But the numbness and tingling progressed up to my chest, and my feet feel like ice, my back feels like fire, and I get shooting pains in my legs. Also, I still have problems with going to the toilet because the muscles aren't working.

It's a similar cluster of symptoms to things like Guillain-Barre syndrome and Lyme Disease, but for every diagnosis they look at, I would be a rare atypical case. For example, I have reflexes where I shouldn't, or the progression of the symptoms doesn't fit the pattern, those kinds of things.

I had a brain MRI and a spine MRI, with no visible signs (doctor is aware that it could be too small to see) of inflammation or lesion or damage. I had a lumbar puncture which showed (if I remember correctly) mildly raised protein and some abnormality with white blood cells.

But they still can't find out what's wrong with me :(

My symptoms didn't change for more than a week, and as I was able to walk, the only real issues were some toilet problems and the abnormal sensations. So the hospital discharged me last week.

Over the weekend, my symptoms developed. I noticed it felt 'heavy' when I breathed, like the muscles had become weaker. The numbness moved up to my collarbone, and my hands became numb in some places and not others. These symptoms have stayed since then. But for around an hour or two, my face became numb, my tongue felt weak and heavy (like it was falling back into my throat), and the muscles in my face felt heavy and were noticeably slow to tense and relax. I have been to the hospital to check that there's no emergency.

Also, I'm not sure when it started but I think I'm having some problems with memory and speech. I find myself pacing backwards and forwards, or going into a room 4 or 5 times before I can do something simple, like switch off a light or get a drink. And I keep throwing wrong syllables into sentences, or replacing words with other words (e.g. generally -> germany).

I'm scared because it feels like there's something spreading through my body and making things not work properly, and I have no idea when/if they'll be able to diagnose me. I feel like at any moment, this problem could get into a bad area of my nervous system and disrupt something really important like my breathing or my heart. If that happens, what if I can't get to a phone in time? Will someone just find me dead? Or if I do get to the hospital, what if I wake up one day and I can't speak, or something worse? It makes me paranoid about every little thing. Yesterday it felt like I had a headache moving through my head. Imagining what it could be terrifies me.

All of this started unexpectedly, and escalated so quickly, and it could keep getting worse like that. I know that right now I'm very lucky to have symptoms that I can manage myself. Maybe someone else here has had similar experiences and could offer some reassurance or advice?