There have to be holes in what I think, but I suspect beating myself into logical submission won't work. It seems to be more of a felt thing than one that is thought.
I think, whether other people think you are thinking wrong or right, you have to acknowledge what is there first and foremost. I do a lot of saying "I know that's the wrong way to think, but right now that IS what is in my mind" - it's not that I'm thinking that, it is that I'm actually feeling it, and to me that's the difference between a core belief that is ingrained deeply into, what seems like my very being, and a negative thinking style.
I'm not sure that I can 'get rid' of those core feelings about what I am. And it seems important for me to acknowledge those feelings and to allow them to be there - not try and change them. I wasn't allowed to say "I feel this" as a child, it was always pushed away and treated as a 'bad' thing to do and I always felt that I was wrong for feeling. And this is why it's important to be heard and I can understand your frustration that this important aspect of what you feel is not being heard.
In terms of a diagnosis of PTSD. I think in the pinned 'what is complex trauma' thread, I shared that I was a mess in my teens and into my twenties, but it wasn't until I was attacked again in my thirties, that I developed full on PTSD symptoms. So to me, treating PTSD symptoms would have been addressing the trauma in my 30's that caused PTSD. But what frightened me more than anything was that I had related earlier abuse to my recklessness as a teen and young adult, and had left it behind to become a sensible, responsible mother making good choices in most areas of my life. And yet, I STILL didn't see the signs of the man I was inviting into my life, being an abuser. So a massive part of my PTSD was that realisation that I was not safe because I could not see who was abusive and who wasn't - a big part of treating that is dealing with the core responses I have that put me at risk of abuse - and they were formed before the incident that eventually led to PTSD.
So yes, the complexities surrounding abuse are so much more than the experience of the actual abuse, and that, for me, is what makes trauma complex. And in addressing that, trauma focussed CBT alone fails to address the non-trauma focussed cognitions that play such a major role in the mind.
I think, in the UK NHS, because of time/financial restrictions on therapy, there is a tendency for therapists to look at the diagnosis and treat that along the guidelines for that diagnosis, rather than look at, and treat the person. I ended up going to a charity that offers free therapy for people that have experienced rape and sexual abuse - without time restrictions, I was able to bring up those seemingly non-trauma related issues of childhood - and this therapist (whose experience was in the field of rape and SA) understood the additional issues that aren't directly related to the traumatic events, but form part of the overall experience of that childhood.
I would recommend googling 'rape and sexual abuse support... [your area]' to see what is available.