I looked up a few things for you.
This link describes the law in general terms. It's fairly easy to understand, but it's not specific to your state.
This link is from the Child Welfare Information Gateway. It describes different types of abuse and has links to many other thing where you can sort of launch a search to see what would happen.
You likely would be left with your mother. After all, she thought it had stopped, she may have thought it was a one-time occurrence, or she can claim to have misunderstood what was going on. What matters is if she can provide a safe environment for you. And the state will check and see for things like basic cleanliness, food, clothing, a bed. Stuff like that.
The investigation will probably focus on you and your father. Since you're a minor, the state may prosecute for you, although you will get a say if you want it to go all the way. BUT, I'm not a policeperson. I'm your average dude on the street who happens to have an idea. You'll want to call and check procedures and find out what would happen, just to be sure.
Anyway, good luck. And we're always here if you need us.
Oh, I almost forgot to mention, generally state protective services, like social services or whatever it's called in NC, are very focused on re-uniting the family if you and your mom do get separated. But I do doubt you'll be separated.