Flu is a viral infection of course. There is only usually one or two prevalent types each year but there are many many variations.
There are also many “flu like viruses” which would be my guess as to what you had as the symptoms you describe do not seem severe enough to be actual flu.
Of course everyone reacts differently to illness and diagnosis from internet descriptions is highly inaccurate.
“my symptoms were similar to bushwacked: completely wiped out for 3 days and could barely get out of bed, then drained of energy for the next 2 weeks.”
sound s like a severe cold to me – not flu.