@PrayersPlz - I'm sorry to hear that you have been through such hell. It's always amazing to me that they tell you to go to an emergency room if you're having a psychiatric emergency, but then they never help. I even told my friend that it would be good for her husband during a time which he was experiencing extreme paranoia, but he was furious and triggered by the forced hospital visit which did absolutely nada.
Benzodiazapines can be addictive, but a lot of this seems to be dose dependent. Truthfully, I weaned myself off of them, but sometimes I kind of wish I had them around. I am definitely not anti-med, but, I believe in using them only when necessary. They might be necessary for a little while to keep him stable, but there shoud be continued therapy with the intent to often reassess drug needs.
C-PTSD I don't believe is included in the DSM V, but I definitely believe it's a real thing. It is usually a result of repeated traumas though. I don't know your SO and it is defintely not my place to make a diagnoses. I think really this is just a matter of difference in words; "regular" PTSD I'm sure is bad enough.
So you mentioned he is currently seeing a psychiatrist but I wasn't clear on whether he is still receiving therapy. Very few psychiatrist deal with actual therapy but I know there are a few. If he is not seeing a therapist on a regular basis, then he needs to, and you could most likely benefit from it as well.
I'm sorry to hear you're having such a hard time! I will think good thoughts in your direction.