I know this is an old thread but did you ever get to the bottom of this? I've been living this life for the last 4 years.It aint nice.
It is a few years later and I still suffer from fatigue, CFS, ME, whatever you want to call it. Basically an unidentified, undiagnosed set of symptoms that can render you very very tired with aches all over one moment but able to function fairly well a few days later.
I had a quick look back at my last comment on this thread and it was 3yrs ago. I stopped visiting the doctors about 18 months back after exhausting yet more specialists. I think the last one I was passed through was a pathology consultant who went through some more in depth blood testing with a view to investigating potential blood cancers and stuff like that that could explain random tiredness. To cut a long story short, all these tests came back as negative and I continue to be given a clean bill of health generally speaking with the exception of a slight Vit D deficiency (no different from many UK people if everyone was tested) and a slightly elevated red blood count that was deemed to be within range despite being on the slightly high side. I had been back for repeat testing on this but with similar results and no doctor was concerned about this.
In a nutshell, no obvious reason can be found for my issues.
The pandemic has started shining more of a light on the sort of symptoms I have experienced. Long covid is in its infancy but hopefully will justify more research being undertaken so that a spotlight can be shone on viral loads and how it can affect some people. The more I read about what long covid sufferers are experiencing, the more I nod my head and say "yep, that is exactly what I have been dealing with for years"
I have always been a healthy person (now 41) who is never off work in many years. My medical history is basically a ruptured appendix with subsequent emergency surgery to remove when i was 31. No other issues. I have however historically always had a very heavy head cold almost every year. Doesn't keep me off work but for 3-4 days, eyes and nose leaking and just basically your standard heavy cold that needs to run its course. As a variant of a coronavirus, I suspect that my body had some reaction to a virus that the immune system continues to react to whenever it chooses. It comes with little warning. Maybe a few hours of coming over a little queer followed by massive tiredness, aches and often frustrating pain in joints, across shoulders, neck, chest etc which in turn results in more tiredness.
Over the years, a combination of listening to my body, resting when necessary and not overdoing it has helped, as has a positive mindset of accepting what it is and not getting too frustrated with it. The only thing I have found to consistently help is CBD which I now take every day without fail before I go to bed.
It is a management issue. Accept, smile and learn new skills so you can do positive stuff when you are unable to do the physical stuff. I took up leather work and installed small golf training aids in my house so I could do some things which gave me the direct feedback that I require from life.
Over the years, I have improved. In the first two years, I had to give up all physical activity apart from the odd bit of shooting. I ceased my golf membership, stopped cycling and generally spent lots of time on the sofa. I am now able to cycle, I play golf a few days a week (not withstanding pandemics) and generally can be active as long as I listen to my body. For example, two weeks ago I was not feeling great and chilled out for a few days to allow symptoms to pass. A couple of days later and I was dragging a muntjac over 1000yds with equipment on my back and I am still well enough today to be back out tonight for pest control.
Balance, stay as healthy as poss and give your body the best chance. And of course, good luck.