YOU SAID:
help me my dad is slapping me
INTO JAPANESE
私の父は私を平手打ちしている私を助けて
BACK INTO ENGLISH
My father helped me slapping me
INTO JAPANESE
私の父は私が平手打ちを手伝ってくれた
BACK INTO ENGLISH
My father helped me slap
INTO JAPANESE
私の父は私が平手打ちを手伝った
BACK INTO ENGLISH
My father helped me slap
That didn't even make that much sense in English.