My parents and everyone who was friends with my sister (1 year older) all deny this is abuse. Basically, growing up from puberty onward it was like spending time with my worst bully 24/7, school, dance, eventually work. She was prettier, and had more ‘popular’ friends. She constantly yelled at me, called me fat, ugly, excluded me from her social life. I remember some hitting. She &amp; my mom would go through my electronics and everything I owned. Once I started making friends, if there was anything they did she didn’t like she would shove her nose in and scare them away. Same thing with romantic relationships eventually, I would tell them about her BS but they just didn’t want to deal with it. There were times my mom joined in and they tag teamed pushing people away to ‘protect’ me. So I learned to keep every relationship long distance, away from the home.

ANYWAYS I became extremely mentally ill, she is thriving with a fiancée and baby. She now literally treats me as a child, not sister nor human. Her &amp; my mom have never been closer because they bond over being parents. 

Is it possible to have PTSD from a sibling growing up?