Hi. Sounds like schistosomiasis, but not likely, because of the symptoms you described.
It could be a type of zoonosis that has not been studied in humans....or more commonly known as unknown parasite like Morgellions disease (which I assume you have already considered).
That would be my official observation. But, going down the rabbit hole, there are plenty of alternative theories. Using iodine is an idea that could hold merit, but I would consider you continue to look for complimentary options as well.
In your particular case, I would recommend frequency type therapy, akin to the "Rifing" that is sometimes talked about here on Curezone. I have never been convinced of the method, but I do reserve the opinion that if performed by a competent operator, it can be effective. These types of contaminating things sometimes respond to electro magnetic disturbances, and electrical impulses.