Keep your hands off me! - Stay away, no contact yet. Get your hands off me! - Stop contact, contact has occurred. Hope this helps! :)

If someone was touching you and you didn't want them to you could say either 'Get your hands off me!' or 'Keep your hands off me!' If someone was not touching you (maybe they were looking at you weird or maybe you had already removed their hands from your body) you could say 'Keep your hands off me!' like a warning. In this case, you could not say 'Get your hands off me' because their hands were not on you the moment you said it.

The literal meaning is slightly different. "Keep" implies that it's a command without a time limit. But the literal meaning isn't really applicable. In everyday usage, they mean the exact same thing.

There is no difference in the context you used. They mean the same thing.

"Get your hands off me" = someone's hands are literally on you. "Keep your hands off me" = "Don't touch me"