No need to apologize
I understand PTSD. However if he is unwilling to get treatment there really isn't anything that you can do for him.
I would suggest that you learn Basic Shielding, Grounding & Cleansing Techniques because as a person who is Sensitive to other people's emotions & energy you these will be crucial to your well being.
If you haven't had a chance to go through it yet,The Empath Survival Programis Phenomenal; as well as, Elise's(ths site's Founder) EFT Videos and I also recommend Donna Eden's Energy Medicine Videos on You Tube.
I especially Donna Eden's recommend:
Energy Medicine 101
The Zip Up Technique
5 Minute Energy Routine
I wish you the best :