You're dealing with a whole lot of stress right now, aren't you? Not only are you still dealing with the trauma of being abused so terribly, but now the family is reacting and putting pressure on you. We understand how this is such a hard thing to deal with, and we're sorry you have to be in the middle of it.
We know you won't believe us, but we'll say it anyway: talking to the cops was the right thing to do. There's all kinds of reasons as to why it was the right thing to do, but we won't take up a whole lot of time talking about it. You were very strong to talk to the cops and tell them the truth. You should be praised for it!
For now, when you get hit with this much stress, your best bet is to 1) find a way to feel better, and 2) minimize the amount of stress that's coming at you. You are totally overwhelmed with what's happened, and if your family is driving you crazy, it's time to block out some of that stress.
Tell them, "I know you guys want answers, and I'll be glad to talk to you about everything. I'm just not able to right now. Bear with me." Even if they seem impatient with that kind of answer, it's perfectly okay to let them wait. They can talk to the cops or other family members and get the information they need (if they really need it.) Your health comes first. They have to go on the backburner.
Same thing goes for your little sister. Since she got moved out of the home, her emotions are going to be all crazy and jumbled up, too. By yelling at you, she might be venting her feelings, and that's totally not right. Some of the things she's saying to you might not be a good reflection of what she's actually feeling. Some of the things she's saying may be completely temporary; she may not believe them later on. Even though what she's saying hurts, try your very best to let it slide. Don't talk to her if she wants to start blaming you for stuff. Refuse to participate in any kind of conversation that's going to hurt you.
Also, if you see a counselor, tell the counselor about the cutting you've done. If you don't see a counselor, tell your caseworker. Keep your caseworker's name and number handy, because that's the person you need to go to if things go awry.
Try your hardest to resist those urges to cut. If you've just started cutting now, you'll want to stop it as soon as you can. There are people out there who cut for years, and they start looking like a cutting board after a while. You don't want to end up like that. Make a list of things you can do when you feel like cutting. Try to distract your brain and get it focused on something else. Do your very best, and then get professional help from a counselor as soon as you can.
Take care of yourself. If you need to talk, we're here by phone, email, and chat. You'll make it through this!