So true: ptsd is a part of who he is, but I'm confident he will find a way to live with it
Sorry to keep cutting in but just wanna make sure you aren't misunderstanding PTSD. You heal from trauma and manage PTSD. It's not cureable. Only manageable and it can pop back up at any time.
You don't "live with it". You process the trauma and heal from the trauma. But that can take a very long time.
But even after he has healed from the trauma, processed the trauma, and has PTSD managed, he still has PTSD. Yeah, it maybe managed enough that he no longer meets the diagnosis criteria, but he still has PTSD and again, it can pop back up later in life at any time. Something can trigger it and BOOM!
You just don't find a way to "live with it". That's not how it works. If you want to still be with him you would want to accept him with PTSD and all the flaws that come with that. Yes, have good boundries but when it comes to him and "the real him" this is it and even if he heals from his trauma, processes it, and manages PTSD, this will still be the real him. Just the symptoms will change. They will be managed. But, he'll still have PTSD. Just managed PTSD. If that makes sense.