It is most unwise to attempt a diagnosis when one is not a professional. Some of the features of personality disorder may seem similar to what your boyfriend experiences, however if he has already been diagnosed with PTSD by a professional, I would trust that diagnosis. You are correct; all of the above could also be associated with PTSD. In fact, many people, diagnosed with a disorder or not, could look at the list provided by Upstream and find that they relate in some respects - for example, those diagnosed with clinical depression may also experience many of the above symptoms. Having similar symptoms or features does not necessarily mean the same diagnosis. When making a diagnosis, professionals look at many factors. The extent of the problem, number of criteria, duration and severity of symptoms, past history (including whether trauma is present or not - trauma is not a requirement for the diagnosis of a personality disorder), exclusion of other disorders and so on. Do be careful to not jump to any conclusions.

Blueeyedgirl, have you read the following article? It is one of the best on the forum, at describing the stress of PTSD, and how it makes our loved ones behave. I found it extremely helpful in my personal understanding of PTSD. I highly recommend you read it, if you haven't already:

Understanding PTSD - Edited