When I was younger my older sister used to grab me and shake me, yell at me. I feel like whenever I hear anything loud or arguing, get physically touched I feel extremely uncomfortable. I recently saw a new therapist and I talked to her about how my sister used to do that. I told her whenever my sister looks at me a certain way, I think back to when she used to do that. My therapist said that is considered a flashback. Ever since that therapy visit. I've been having nightmares of my older sister, doing it to me again. I'm helpless and can't stop it, just like when I was little. These nightmares are frustrating me. I don't know why they're happening. I know a old therapist, considered diagnosing me with PTSD but never did.

Could this be PTSD?