Sorry for the late reply. I don’t follow every posts so if it’s not addressed to me, I don’t get notified.
Some recovery stories are longer than 3 years. In my opinion, 3 years in more like the minimum time and it goes up to 7-8 years. But that doesn’t matter. The disease is in my opinion epigenetic. Epigenetic damage can heal spontaneously by itself but may very well not, especially if it extensive. So the recovery period, in my opinion, has more to do with taking pro-active steps to heal epigenetic damage, plus whatever the body will heal spontaneously without help (if it will at all).
Someone sick for 12 years imo is unlikely to recover spontaneously (although he might, if there are other unknown changes in his life). But the same person taking pro-active actions to heal epigenetic damage might recover 3 years after consistently taking those actions.