02/20/2013 at 10:30 AM EST
Just days before her suicide
, Mindy McCready was plunged into despair after she was served with court papers proposing that her two sons be sent to live with her long-estranged mother.
"The most important thing are my babies must come home," she wrote in an email to her private investigator friend Danno Hanks, who tells PEOPLE in this week's cover story: "She lost all hope."
McCready, 37, was found dead Sunday of what authorities said Wednesday was a self-inflicted gunshot wound to the head on the porch of her Heber Springs, Ark., home, the same spot where the body of her boyfriend David Wilson
was discovered last month, also with a gunshot wound to the head.
The long-troubled country singer
and mom to Zayne
, 10 months, and Zander, 6, had recently gone to a court-ordered rehab center. She left for police a harrowing scene of death and filth.
The house reeked, food was left out and dog feces were everywhere. Bottles full of prescription pills sat on the nightstand and in the bathroom, according to a police source. Also found: the body of a dog, whom McCready apparently shot
before taking her own life.
"People talk about a train wreck, but the world lost a real person, a human being, a mother," says country singer Chely Wright, a friend of McCready's from their early days in Nashville. "I'm praying for her kids."
For more on Mindy McCready's troubled life and tragic death, including inside accounts of her troubling behavior, the latest on the investigation into her boyfriend's death, and exclusive interviews with her closest friends and her former fiancé Dean Cain, pick up this week's PEOPLE, on newsstands Friday