So… This is a combination of a confession and a question. I have researched this again and again, yet I have found nothing that helps my situation.

I have PTSD that was caused by my family. I have been officially diagnosed but I haven’t told anyone outside of the one who diagnosed me. It’s interfering with my daily life and causing my family to yell at me and do things that trigger it even more. I feel like I really need to tell them so that they understand what I’m going through, however I don’t know how. It would hurt them so much if they knew.

The PTSD was initially caused by my aunt who has severe mental disorders that cause her to yell and make a lot of (100% empty) threats to the people around her at random. This put me into a very fragile state of mind after my dad and I moved in with her when I was eleven or so.

As a result of her outbursts, my dad began having lots of built up anger from my aunt and he ended up releasing most of it on me. He begun to yell at me for things I didn’t do, make hard punishments for small errors, and pile me with chores. He stopped working and it seemed like I was doing most of the work. I found that my room where I could cry behind a locked door was the only comfortable place for me.

Then came the day that as a punishment, he took my door off the hinges. He left it like that for the start of the hardest night of my life. I realized then how unsafe I felt in my own house and had my fist panic attack. I never slept that night. My PTSD began to develop so quickly, that whenever the door to my room was open, I got an immidiate flight response. I could never finish whatever task I was given because I was so scared whenever the door was open. It would sometimes stay open for days, all of which I would never sleep.

Anyways, my aunt begun the decline, but my single father caused the PTSD to develop.
How do I tell them?

TLDR: My dad who I used to be pretty close with gave me PTSD that really affects my life. How do I tell him?