OP, I'm going to say this in the kindest possible way. People are sharing their experiences in an attempt to help you - not to condemn you to years of therapy.
Sexual assault is (sadly) hugely common. The NHS provision for mental health is very poor. Your situation (again, very sadly) is in no way unique or unusual.
Posters who have referred to "complex" PTSD are talking about the PTSD that comes from repeated exposure to trauma - often in childhood.
People who have grown up in an abusive environment often need years of therapy to work through what has happened to them - especially if their childhood development went on through those years of trauma.
Nobody has suggested that you require three years of therapy - rather they are sharing their positive experience of therapy with a view to giving you hope that you can recover.
Writing snarky strike throughs about the cost of three years of therapy to someone who has shared their recovery from having a PTSD diagnosis to not is really rather unkind.
If you are interested in learning more about how trauma services slip through the cracks of the NHS it's worth looking at PODS:
information.pods-online.org.uk/what-can-i-do-if-i-cant-get-therapy/
To make it clear, this is a resource site for people who have survived complex trauma and developed a very complex mental health condition as a result - far more complex than a standard PTSD diagnosis.
As the site owner explains, people slip through the cracks and often have to rely on private therapy. And very often it works for them.
By linking to this site I am not suggesting your dissociative, or that you experienced childhood trauma. I am trying to explain to you that your poor experience of the NHS is by no means unique and that people have recovered very well from very significant trauma without having to go down a medical route.
I can't speak for goldagainsthesoldier but from her posts I believe she was trying to give you hope that you won't be stuck with this medical diagnosis forever, and that with the right help - that needn't be costly - there is hope for you.
I hope things begin to look up for you.