Of course it's okay that you commented. I am sorry to hear what you went through with him. The "sneakingly" part sounds really familiar to me. My therapist told me my ex is more "covert" which means his way of belittling me isn't very obvious. He would "jokingly" throw jabs at me in public and at home. It took me awhile to realize it wasn't right to be treated that way. As I understand it, a lot of the covert behaviors can be hard to process at times because they aren't obvious.
While I am sorry to hear your ex has PTSD, it still doesn't excuse his behavior, in my opinion. I am sorry if that sounds harsh. I have PTSD for a different reason and I don't know him or what he's been through as a combat vet. Having said that, I am working really hard on my behaviors. Having PTSD doesn't excuse me from behaving badly. I struggle with this sometimes because there were times when my ex would trigger me on purpose claiming he was helping when all he really did was make it worse. He admitted to triggering me on purpose and he pushed my buttons on purpose claiming I just needed to get my anger out. I had just started trauma therapy and didn't know how to handle the anger and intense emotions that it brought up. While I believe we are all responsible for our behaviors, does that still apply when someone knowingly pushes you to your breaking point and you don't know how to make it stop even when you beg them to stop and they don't? Then they tell you you're unstable? It's still very confusing at times and it's awful.
As for your feelings of guilt, I believe it's okay to feel however we feel. I felt shame and guilt for a lot of things. Therapy helped me to realize the guilt I was feeling wasn't actually mine. I'm not sure how to explain it but she called it "carried emotions". The guilt I felt was actually his guilt but I took it as mine. Once I realized that, it helped me a lot.