There are many strategies and systems which have stood the test of time and are just as effective today as they were 10, 20, or even 30 years ago!
Why couldn't this cycle of yours, if it exists, simply be restarted at x number of trades or x amount of time or at x point on the curve, with a new strategy if necessary. Original risk capital will have long been withdrawn anyway so it's not going to be a losing proposition going forward whatever happens. Rinse and repeat.
Mathematicians and academics are the worst when it comes to failed traders, they analyse the hell out of why they failed until they come up with a reason which exonerates them from blame or failure, instead of just accepting that maybe they're not cut out for it. That's my theory!
I'm sure you're very good at what you do, accept that trading is not your forte but it is for some people.