After a 6 year struggle with DPDR on an almost permanent basis, I figured out the cause and fixed it. : Depersonalization
Interesting and great read about a guy who suffered brain fog, depersonalization/derealization, seeing life through "glass", memory issues and anxiety, triggered after one morning of waking up with a sinus infection, lasted 6 years. He also began suffering from IBS, low sex drive, insomnia. Not sure if there is a connection, but my "PFS" began with a sinus infection, also you see this in CFS sufferers.
He talked about what eventually cured him was his doctor "prescribing" him breathing exercises, his anxiety was causing him to experience something called "unconscious hyperventilation" where his breaths became short and fast with irregular rhythm. The condition was called Hypercapnia, causes dizziness, brain fog, DP/DR, yada yada, but can be triggered from a traumatic experience/stress. Frequent exposure to short, irregular, anxious breaths eventually can lead to CO2 toxicity. Messing with vision, cognitive function, all sorts of things. I think a ton of PFS sufferers, especially on forums like PH look so long for a diagnosis of what is wrong with their bodies where a lot of the symptoms are arising from things like anxiety and short/shitty breaths.
I frequently see things like breathing exercises, avoiding pesticides/chemicals and eating organic when looking through recovery stories of people that have never touched fin, but become chronically ill with unexplainable illnesses. I'm a firm believer that a lot of PFS symptoms are caused by nothing but stress and panic, as opposed to damaged 5-ar, especially mental symptoms. If you're not improving but doing everything on the protocol, maybe make more of an emphasis of doing breathing exercises, picking up fun hobbies that allow your mind to enjoy itself, and meditate to find a place where your mind can relax and rest. Constant worry about PFS and symptom checking is going to keep you in this hell longer I believe.