Anxiety related to abusive dad

My dad's been getting involved w/this religious hate group the last couple years and getting more aggressive and violent. I didn't experience much of it but he's been very verbally and occasionally physically abusive towards my mom and sister. My mom's never reported any of it but she did get him to move out and is working on some legal action to keep him away. He still drops by their house and yells at them and rants about his ideology, and sends us all links to videos he watches. I'm scared I'm gonna get a call oneday hearing he did something to them. And today I got another email link from him & I started having trouble breathing. I was fine after lying down for a sec and focusing on my breathing. It wasn't a full on attack but it felt like it coulda spiraled into one. I've never experienced anxiety from someone's actions other than my own and I feel helpless.