Have you let him know you found this forum? To me it alwase seems the best first step is to find out your not alone and that so many others go through the same things you do. To talk to someone who also has PTSD and shares the same frustrations and anger and fears as you do. I would let him know you found this site online and try and get his curiosity to see what others are talking about regarding there own PTSD or something along that line.

Good Luck.. the first steps are alwase the hardest!