I need serious advice

⚠️Trigger warning⚠️ rape, depression/anxiety, panic attack, self harm

So I’m currently living/working 2.5 hours away from my family, and have been since the beginning of April. I was talking to my mother because I was telling her about two pet baby rats I got Saturday (my friend/roommate has snakes and if the rats she gets them don’t get eaten she keeps them as pets, she has two or three rn I think and I started getting attached so me and my bed went out and we got a couple for me).

I asked about me coming down to visit sometime if I could get the time off work or if it would be best to wait until the holidays (I was planning on bringing my bf down to meet her when I did so) and she just said “Call me, there’s something I have to tell you”.

Now, my mother isn’t one to make a big deal about things. A couple years ago I decided to explore my sexuality a bit and dip a toe over the other side of the fence if you will, and I told my mom I needed to talk to her in person, and it wasn’t something that was a phone convo. When I got there, we talked and I told her that I thought I was Bi, or at least Bi-Curious. After talking to her, she just goes “and you couldn’t tell me this over the phone because? I was freaking out thinking you were going to tell me you’re pregnant!” So when she told me to call her, I knew it had to be important.

So I called her, and the first thing she asked me is when I last spoke to my sister. I told her I was literally just messaging her (I was telling her about the rats as well). She asked if she told me anything, and I said no, getting concerned.

At this point my mother takes a deep breath and, in a voice that sounds like she’s holding back tears, says to me, “Ariah was at the Clinton pool, the other day, about a week ago, and... she was raped.”

My sister is 13, just about to turn 14, I don’t know if she was there alone or not, her parents both work and they don’t live far away from the pool, when I lived with them we would go down there all the time and swim in the summer. My mother was practically in tears telling me about this, we don’t have much information right now, at least not that I’ve been told, she said it was some 15 year old she met, they told the detectives everything they needed. But now my sister is afraid to be in the house by herself, when she would normally be happy to have the house to herself; she can’t sleep on her own anymore, she’s been sleeping with my mother downstairs in the living room on the couch; she’s not doing so well, and neither is my mom. Her father wants to kill the guy, and I don’t blame him. I do too.

When she was telling me about it, I started shaking and I was getting furious, and I could feel my chest tightening up after a few minutes and I could feel the onset of a panic attack. I feel like I needed to cry but I couldn’t, I couldn’t stop shaking, I just wanted to stab something. I was lucky because my boyfriend was still here and he was able to calm me down before I did anything rash, but usually when I get bad panics attacks and my anxiety starts acting up like it did (all I could think about was all the times I had taken her down there when I’d visit in the summer, when I was still in high school a couple years ago, just the two of us, or even times when I’d go down there with my friends, and how lucky we were nothing happened to us then) usually I end up cutting. I’m trying to break from the habit but now that I’m stressed out and panicking and angry (especially since I can’t really do anything) and my bf went home so I have nothing to counteract everything that’s going through my brain, it’s getting bad again. My mind is getting violent..

What should I do? I cant do anything to help them, and it’s stressing me out very much.. any advice?