Around January ago over a few days I felt absolutely awful. Started after I got home from work on a Friday sweating, feeling knackered and a massive headache. I never feel unwell or get flu symptoms so it was strange. It lasted the weekend then I have just felt knackered since, but think that’s more down to stress at work and other things going on.
Symptoms I had seem to match what this is like though, but guess most people won’t ever know unless they are tested. It’s probably been around a lot longer than the last few weeks/months