Mine never makes me tell her anything - she says she is happy to listen but she doesn't need to, which is good because I could never actually get it out.
She often asks about how whatever happened makes me feel, not what actually happened.
You said you originally went for some coping mechanisms for snapping at your family. T shouldn't need to know what happened in the past, just how you feel at the moment and your emotions that lead you biting your families heads off