OP, I am so sorry you are living with the long term results of trauma.
You don’t have to ‘justify’ it in order for MN to decide whether or not YABU.
AIBU however, is definitely NOT the arena for serious emotional advice.
It sounds as if he has generally been supportive.
It may be that your DH now feels helpless to help , as you are still so badly affected.
It may be that, feeling helpless, he cannot actually bear to see you in so much pain.
I agree, leaving while you were hyperventilating was pretty hard. But he may have needed a direct request. Given that he may think ‘whatever I do doesn’t make it better’.
I have no experience of PTSD so don’t know what to suggest for getting through today. But look after yourself in any way that the counsellor suggested, or things that make it easier for you to manage the symptoms. And then later, when calm, perhaps ask your DH how he feels when you are so upset?
Maybe both of you could seek help together?
Whatever happened must have been traumatic for him too, at the very least watching you in pain.
Sending virtual tea.