Forever Lulu (2000) on Netflix

Plot summary

Ben Clifton and Lulu Mcafee were sweethearts in college, their intense affair shadowed by her untreated mental health condition, which ended in her hospitalization and their separation. Ben has since become a successful writer, and his marriage to Claire has turned distant. Newly discharged from the facility where she was treated, Lulu tracks him down with the news that fifteen years ago she bore a child and gave him up for adoption. She intends to meet the boy on his fifteenth birthday, and she wants Ben to travel across the country with her. He agrees at first because he believes he must keep her from harm.