I don’t think you do get out or start afresh. That person has imprinted themselves on your heart and mind. They will always be there to some degree or another. There is no undo button or CTRL+Z to clear the page. The story just continues to get written. With time and new experiences, that person recedes into the background as other characters move into your life and foreground. But with time, they too will recede and fade.

To accept the impermanence of all things in life is the letting go that helps you find a new strength and resolve to move forward.