I can relate to this a lot :)
I am DID, so I have alters... Now, when it comes to this, I am accepting that I have PTSD, but some of the alters sorta aren't and they are instead in denial, which makes me suicidal. It's much easier to work through problems when accepting something is a problem.
Now, if you are more interested, you could always look up the accuracy and the chance of misdiagnosis when it comes to PTSD, but from experience, it's more common that someone with PTSD is misdiagnosed as something else than that someone is wrongly diagnosed with PTSD.
Yes, there is always an option that your theraphist is just sucking money out of you, but ask the question, whether the theraphy is something positive, that helps, or negative, as PTSD or not, theraphy can be quite useful.
Hope any of this helps and good luck in recovery :hug: