I have physical health problems that make my life exhausting and empty. I had this infection some years ago that I can't seem to recover after, or perhaps it was all the antibiotics that destroyed my immune defence system. I am tired and exhausted everyday all day.
I had the same issue about 8 years ago (still do) my physical health just collapsed, 4 years before I got a proper diagnosis to be told there is no cure, I changed my diet and lifestyle, took years to get to a functioning state and the depression was immense as I used to be an active person. Friends soon desert you too, only a few hang on (legends!), not that I even had a lot of friends in the first place. I'm not sure what the health service is like where you are (free or not) but I had to do a lot of kicking off to get diagnosis, did my own research etc. You sound like you are describing CFS.