One year after Cory Monteith passed away on July 13, 2013, the late actor's mother, Ann McGregor, spoke with 'Good Morning America,' giving a heartbreaking interview about dealing with her son's death.

“The last few days, I'm 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.”

The 'Glee' star was found dead in a Vancouver hotel room last July as a result of a drug overdose from a mixture of heroin and alcohol. He was 31 at the time.

McGregor says that Monteith started suffering from drug problems as early as the age of 15 and believes that her separation with her husband, Joe Monteith, might have been the trigger. "I think that was the turning point. He had a lot of emotional things he was trying to figure out -- lot of it was he really wanted a relationship with his father. I think when a child gets invalidated they keep reaching even harder. They want to find out why.”

But she doesn't place blame on anyone, including Hollywood, on Monteith's choices which led to his untimely death. “I don't think blame is a good thing to do; that was his choice."

She also revealed that she still keeps in touch with Monteith's former girlfriend and 'Glee' co-star, Lea Michele.

“She texts me and e-mails me," McGregor revealed. "She’s hurting too. You see the sadness. I know her pain.”

On Sunday, the first year anniversary of Monteith's death, his fellow 'Glee' co-stars shared thoughts and remembrances on Twitter, including Michele herself, who tweeted a sentimental picture.