Hey there, khvioet:
I'm not Sam (obviously), and I don't know if you'd rather continue your larger conversation with her, or if you're okay talking to me or others as well. Let us know, and we'll do this in whatever way you prefer.
But I did at least want to say that in reading your response here, I understand. I think it's very complex, and there's a lot to consider with all that, including some of what you've said here, particularly when it comes to what you will need as the actual victim and survivor here. But that certainly doesn't have to be anything you do any faster than actually feels like it is right for you.
But I do want to make sure that if, for now (or ever, but certainly now), you're not going to tell anyone in your family, that you can make that choice AND still get to be safe.
Your cousin made clear he's dangerous and abusive, however you may feel about him, and that he will do you or others harm. So, at the very least, can we make sure, there's a way for you to never be alone with this cousin ever again? And that you have a plan for how to be sure you can get out of things like sleepovers where he is, or, ideally, even having to see him and interact with him? Chances are, we can help you figure out ways to do that and be able to not tell your family yet if that isn't what you want, if you don't think you can work that out on your own or with your friends (who I'm so glad you told: it feels so terrible not to tell anyone).
Never doubt that a small group of thoughtful, committed citizens can change the world. Indeed, it is the only thing that ever has. - Margaret Mead