@miffli - I admire your patience enormously, although I do wonder if it's more you are totally "battle weary" and can't face another fight? However, to my point, I think you are actually being far to nice to your Doctor.
Your GP doesn't seem to understand just how you feel about your predicament, and how unwell you are feeling. If you are unable to be up and about, you are unwell. He is quite happy for you to wait until some sort of magical gap appears in their super stretched diary. Of course, this isn't helped by the coronavirus gubbins going on at the moment. I feel sure they are seeing a lot of patient panic, whether justified or not.
In my view, (and if it were me, I my head would be exploding from frustration), you need to be seen sooner than "sometime soon". In your shoes, I would be asking for an urgent appointment. if one was not forthcoming to be seen this week (Yes, I know it's Thursday already), then I would ask for a home visit. I wouldn't expect to receive a home visit, but I would hope it might focus their minds on how unwell I was feeling.
If having done that an appointment was still not forthcoming, I would consider going to an urgent care walk-in, or to A&E. If you rock up to A&E (and trust me, I'd be feeling devastated if it came to that), it costs the surgery something like £75, so they are not going to want that to happen.
If all of that doesn't bear fruit then a formal complaint is in order. If you are talking about feeling as if your time is near, and in lots of ways you wish it would hurry up, you are not in a "wait and see" situation.
It's time to get serious. It's time for action.
Actually, in your shoes, I might actually have a tearful tantrum with them - if I could find the energy.
(I've actually been thinking back to when I was frustrated beyond measure with temperature regulation issues. My GP was incredibly supportive, but, by her own admission had no clue how to help me really.
I wrote a couple of letters to her, prior to telephone consultations, in which, aside from the material facts, I just wrote about how I was feeling - low mood, frustration etc - from the hip, so that she really got it. Probably one or two of your posts on here could be the bones of a letter to your own GP.
After one such letter, my GP phoned me earlier because she was concerned about how down and frustrated and low I had expressed myself as feeling, and asked if I thought I had depression. I didn't I'm sure, but sometimes it is good they know, warts and all what gives.)
Miffli, were I closer, I'd offer to advocate for you. I know some folks have used services, such as these folks. I think this sort of service is available in most areas, and it could be worthwhile putting a call in, just to see if they have a view on the way forward. I know if it comes to an official complaint, these would be the sorts of folks I would use as a sounding board, or to advocate for me.
https://healthwatchnorfolk.co.uk/
Miffli - something has to give here, and it can't be you!