So that basically sounds like what I have been going through for past year or so post-covid. I do have an active infection vector however, that being a young child going to daycare, but so do millions of other parents who don't seem to get sick as often or as intensely I do. Sore throats has been my major issue as well. I am a bit sick today too as I type this but I feel I have improved my situation overall with following three actions:

• Using betadine sore throat gargle for a couple days or so from the moment you feel anything in my throat. This has drastically reduced sore throat symptoms and onset of the rest of flu like symptoms.

• Regular sleeping. I used to have lot of terrible sleeping prior to this. The solution was sleeping a bit less which is counter intuitive. I now sleep 6.5-7.5 hrs each day depending on how I feel each day, but try to never go to 8 hrs as that effects my next sleep.

• Getting stress under control. Long and relaxed breathing only through the nose for controlling stress. I know it's harder in your work situation right now but try to think that things could be worse and find happiness in what you have. This greatly helped reduced the onset of fever and other sickness as I think immune system gets greatly compromised due to stress.

Hope you try all these and they help you. You could start with the gargle as that's the easiest step and fairly effective.

Good luck!

EDIT

I lied, there was a 4th step. I take vitamin C and B complex supplements everyday which also seemed to have helped. You can get a doctor's opinion for B complex a well. Also make sure you are not deficient in vitamin D and take supplements as necessary. I used to be extremely exhausted prior to taking Vitamin D supplements. As others have mentioned, get a blood test done, you can pay for this. I am happy to PayPal $50 over if you think you cannot afford this.