Unfortunately it's something we'd all like to know.
Fortunately for me, my POIS started later in life but we will try here to help people like you to not have to live the rest of your lives with this problem.
I feel the answer is closer. We can try to push the research program as much as possible, in my opinion, our only solution.
POIS can create other problems like CFS (Chronic fatigue Syndrome) and others, or put borderline afflictions, like ADD or depression, over the edge, so especially if you find that you are never out of POIS even after a month of abstenance, you should look at seeing a doctor for parallel illnesses. If you go to a doctor, don't mention POIS, let him evaluate you as a "normal person". If they can help at least partially, it would be sort of like a "weeding", clearing out the background stuff a bit so we can get down to treating POIS.
I think that it triggered from one day to the next with puberty, your POIS inadvertently triggers some other imabalance. Your symptoms are principally cognitive?
Tell me about niacin. For me it clears al the ycuk of the first two or three days and all of the cognitive crap. Just leaves me sometimes with muscle pain if my flush was not string enough.