(CNN) - The mother of late "Glee" actor Cory Monteith has opened up for the first time about the death of her son.
Monteith's mother, Ann McGregor, sat down with ABC's "Good Morning America" on Thursday, saying that she's only recently been able to come to terms with Monteith's passing.
On July 13, 2013, Monteith was found dead in a Vancouver hotel room at age 31. A coroner later ruled he died from a lethal mix of heroin and alcohol.
It has been within only the past few days, McGregor said, that she's "beginning to accept it."
"The loss is horrendous," McGregor told "GMA." "Until three days ago, I couldn't look at a picture of Cory. So there's been progress."
McGregor has kept in touch with Monteith's on-and-off-screen love interest, Lea Michele, and said the actress reaches out to her via text messages and e-mails.
"She's hurting, too," McGregor said. "I see the sadness; I know her pain."
Monteith, who came to fame on Fox's "Glee" as the affable jock Finn Hudson, had a known history of substance abuse. He said in a 2011 interview with Parade magazine that he began using drugs at age 13, and by 19, he was sent to rehab.
Three months before his death in 2013, Monteith voluntarily checked himself into a treatment center to seek help for substance abuse.
Looking back, Monteith's mother said her son was struggling with "a lot of emotional things he was trying to figure out," including his relationship with his father.
When "Cory was 15, he did a code blue. I think that was the turning point," McGregor told "GMA." "I remember after Cory's first OD, the drive we took. All I did was stare into his eyes and hug him and look at him, because I had this feeling (of), 'I really want to know him, because I'm not going to have him my entire life.' "
For those in similar situations who would look to McGregor for advice, she responded that she isn't sure she has the answers.
"I don't think we have power to change the choices they're making," she said. "I think with the kind of connection Cory and I had, if we couldn't prevent that situation, I don't have the answer. What could I say to them? Live every moment."