Hi Veevivianvee,
First I want to say good for you for seeking therapy and do not underestimate how much you know internally about your life, your relationship and this therapist.
Second, I want to say anyone who has PTSD can also have personality disorder or not.
Third, I want to say even though the most repeated chant is narcissist cannot be cured, I personally disagree with that and I have my reasons.
I also want to say even narcissist are abused as children and there is some serious developmental delayed or blunted. There is a lot of information online and otherwise. so in other words, even if your guy is narcissistic that does not mean, he should be in jail, he too can change.
Every baby has a narcissism developmental phase and some people got stunted and stop there just like many others like us and we are all here learning, healing and moving on to become better adults.
Now I want to say few things about your therapist.
I had a therapist one time that was great in trauma (I am realizing this now) but god she had the worst bed (or chair)side manner. She was dominant, narcissistic herself, and basically believed (I think) to break the clients down and build them back again...I think a person said above some therapist who do not know about trauma can truly drive a client to suicide. I believe this too. and this therapist either drove her clients to depend on her like a baby on a nipple or they ran away almost throwing their clothes (going crazy). She had great theories about trauma and knew a lot but her execution was dangerous. This is my experience. I started to go a bit kookoo and all my defenses came out against her and I was exhausted and thought I am going to go mad. So I left unceremoniously by leaving a voice mail and asking her never to contact me! now I know, if she had an ounce of empathy, and patience, she actually had the right theories. IMHO, I needed to break down and build back but in a safe space which she did not offer.
Your therapist sounds like that. She sounds (as mine did too) to first get you isolated from all the other people in your life and then break you down if you are the one with PTSD.
However, also you may have to ask, maybe she right? if you are co-dependent, in order to be a co-dependent one needs the co! and usually that co is a narcissistic person who benefits from your engulfing them.
I think you have a lot on your plate and I truly feel probably your therapist is right and your guy is right and more importantly you are right and also the opposite.
But if you are feeling strong defense about this, look deeper. If this therapist didn't touch a cord, you would be like if a person told you you are obese and you are underweight. You would be what is this person talking bout? But it seems, the therapist hit a cord of something that is worth more exploration rather than automatic defense.
I really hope things work out for you.