Thanks for sharing your hypothesis, Hosamitaha.
I see POIS as a group of related ailments having the same triggers and causing similar symptoms, and it is clear that many POIS types have a strong neurological component.
I, too, think that many POIS symptoms are similar to what we see in CFS/ME, and in long COVID, and it has been discussed here, on the forum. I also think the exotoxicity has a central role, that is why I use TDO and IDO inhibitors in order to control my POIS symptoms, among other things.
Somw years ago, I also created a thread here about the similarities between a POIS attack, and encephalitis. Inflammation in the brain sure seems to be an important aspect of POIS.
Carbamazepine had been mentioned before on the forum, There is even a thread from a member who eliminated his POIS with carbamazepine and/or levetiracetam, while taking those for temporal epilepsy ( see
https://poiscenter.com/forums/index.php?topic=4583.msg49301#msg49301). But, as usual with POIS, this solution will work only for a certain proportion of POIS sufferers, and not for the others.
Some POIS types seem to be more systemic than just affecting the brain, like those who have strong allergy symptoms, joint aches, intense flu-like symptoms, dermatologic problems, and so on. But extreme fatigue, mood swings, difficulty concentrating, etc, are very often present, and point to neuroinflammation in the brain, just like you discuss in your hypothesis.
I am not surprised to read that this member has to limit his sexual activity in order for his control method to stay effective. I experiment quite the same with my own pre-pack method. If too many repetitions in a short time period, it will not contain my POIS symptoms anymore.