Please need help

Theres one manga where this girl is on her 18th reincarnation. She has kinda seen it all causing her to be kinda emotionless. She goes to her mothers firends house where she meets a small boy who keeps calling her witch and she promises to marry a him. The boy mother dies and he wants to go to the amusement park cause when his mother was alive he promised her. Turns out noone can take him there except our female lead. Long story short a car accident happens and the female lead dies while protecting boy. She reincarnates again with boy all grown up but suffers from some mental trauma. WHAT IS THE NAME