I think I might overreact if people don't mind their own business
Why are you going to overreact to them?
I'm overreacting because I'm so mad with them
You shouldn't do that, it's wrong to get mad at strangers. If you worry about controlling your anger, just tell them that you are not interested in talking.
I can beat them up if they don't go away.
I hope that you are exaggerating, because reacting with violence is always wrong, and it could get you into serious trouble. If people are being too nosy, just tell them that you don't want to talk, or try to end the conversation. They will take the hint without you having to get angry.