Am i wrong for yelling in these occasions?

I have never screamed at someone like I have at my half sister. I never scream or yell at others really but my half sister broke my limits 3 times now.

1. Car incident She was screeching it was super high pitched and was overwhelming fight or flight kicked in and i screamed “STOP!!”

2. Chair incident I went to sit down she starts crying i sat in her chair (It was my computer chair) and after 20-30 minutes of her screaming crying and doing things like hanging of the back of my chair. It caused me to scream at her yelling “STOP” twice on 2 occasions about 10 minutes apart.

3. Let me sleep I was laying down and she started hitting me and jumping and landing on me (Purposely) i hide under my blanket and then she jumps on my head twice. After the second strike i yell “Stop!”

I was a little kid once and was definitely annoying but it gets to an extent were it just feels upsetting because i cant really do much at all. All these times this happened because i was pushed past my limits and could no longer take it. Not hating on my step mom or my dad whatsoever but it’s stressful especially when I want to be left alone (I hate doing things i prefer staying inside)

Anyways did I do anything wrong? I feel i didn’t and dont regret it.