Ask HN: Anyone else feeling more fatigue lately? Thoughts on fuzzy Covid states

So every since May I felt like I have been experiencing more fatigue lately.

I have taken the RT-PCR test last week and got back a negative result.

Still, I might have caught the virus at one point (and hopefully defeated it). What is baffling is that in the recent months I felt more tired in general and needed more sleep.

Anyone else feeling more fatigue lately?

Is it possible that 99% of the human population currently have the virus inside thier bodies (though most have it in a small quantity and only the considerably severe ones get detected in tests like RT-PCR)?

How fuzzy is state of covid-19 infection?

Anyone knows any good papers and studies to read up on that? And in general what are some good places (on-going research, virology textbooks/online courses, etc) to start learning about the fuzziness of viral infections?

Can it be that defecting the virus in the human body is like trying to solve a computational problem, and due to mutation everyone has a slightly different variance of the virus so our bodies are all trying to compute solutions to a particular set of the variances (where "solutions" correspond to antibody production, etc)? And when the virus exists in considerably small quantity it is fine (we probably don't feel anything but we may still infect one another with our own covid variances e.g. through saliva), and as the quantity of the virus accumulates, our immune system kicks in and try to compute the solutions (and that's when we feel fatigue though it's still too small of a quantity to be detected)?

And perhaps this is why masks work? (so we are really just trying to reduce the combinatoric richness of covid-19 variances inside each of us by reducing the transmission rate)

What are some existing theoretical ground on this? And where can I learn more?

Thanks!