I've never been formally diagnosed as having cPTSD. But I'm quite certain I could be. The background screaming in your head, you refer to, is something I have experienced for the majority of my life... at least as far back as I can recall.

Years ago there was a type of therapy that was referred to as "Primal Scream" therapy. There was a quite popular book available titled: "The Primal Scream". I never did any of that type of therapy. I do vaguely recall having read the book, although I don't remember much of anything about it. But I do recall relating to the concept of a "primal scream" because even way back then (sometime around the 1970's?) I could hear that screaming in my head. I still do...