Lava,
Thanks to Open Eyes I now have read Re:PTSD/Dad and I will would like to add my support.
I know at one point my ex-husband wanted to disown his parents, it would have simplified our lives at the time, but he did not and we accepted them for what they were, and took steps to protect ourselves from emotional blackmail. It was hard to love those that can hurt you, but we did our best. That is all we can do.
Currently my depression is a mystery to my father. He has cancer and the side effects of his meds sounds very much like depression pain. Yet I am 'not sick' and he is and I can not change his mind, so again I do not go to him and expect support.
I do not know if this helps, but relationships can be so complicated and I am the nut that fell off my fathers tree-

so i am not great at relationships and communication. My PTSD is related to my father in the lesser degree as my early childhood was one of observing parental fights, insults and generally trying to stay out of the way. The major PTSD has to do with CSA unrelated to family.
Trying to help those that do not want or know they need help requires incredible strenght courage and fortitude, and that is not easy. You are showing courage by trying to understand and I wish you all the best.
Gently 1