IN PHOTO: Lea Michele
IN PHOTO: Lea Michelle, from the TV series ''Glee,'' poses backstage at the 70th annual Golden Globe Awards in Beverly Hills, California, in this January 13, 2013 file photo. Credit: Reuters/Lucy Nicholson

Cory Monteith's died more than a year ago, but mother Ann McGregor admits that it has been one of the hardest years in her life, if not the hardest as she was locked in her grief.

While it is understandable that a mother will grieve so, Ann McGregor, 63, shared to ABC News in her first interview ever since Cory passed away tragically that "until three years ago, I couldn't look at a picture of Cory."

McGregror claimed that the past year in the way of son's demise because of heroin and alcohol overdose in July 13, 2013, has been "horrendous."

The only way to cope was to also talk with people who share her immense grief. Even though Lea Michele, Cory's longtime love and Glee co-star has strongly braved the grief and the loss, McGregor claims they both shared a great pain over the loss of Cory. Lea may be seemingly moving on with her life now and starting to date, but the sadness had been and still is, there. McGregor said she and Lea constantly talk through emails and text messages.

"I know her pain," McGregor said to ABC News. "She's hurting too ... you see the sadness."

McGregor shared that she also believes that Cory was already "easing himself out of" showbiz when this tragedy happened. He was already planning to lease a home in Vancouver, Canada when this unfortunate event took place. She also shared that her "Baby Bear," the nickname she has for Cory is not to blame. She said no one is, not even Cory's dabbling in show business.

"I don't think blame is a good thing to do," she said. "That was his choice."

According to McGregor, Cory is already engaged in substance abuse issues at just 15.

"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 [estranged] father.

"I think when a child gets invalidated they keep reaching even harder - they want to find out why."

However, despite of what she went through with Cory and what she knows of substance abuse, she said she cannot give a lot of advice to parents who may be experiencing the same with their children.

"I don't think we have power to change the choices they're making. 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. Grab the second."

Last Sunday, on Cory's death anniversary, Lea Michele led the Twitter tributes over the Glee star, Mail Online UK reported.

She tweeted: "We hold you in our hearts today, and every day we remember your smile. We will love you and miss you always."