In an interview with Newsmax TV to promote her new book Falling With Wings, De La Garza revealed that she received word of her daughter's overdose the way many fans did: via friends texting her about news that they saw on the internet.
After her phone was flooded with texts offering sympathy for Lovato's situation, De La Garza received a call from her daughter's then-assistant, Kelsey.
"Kelsey was rambling like she's obviously been through something terrible and she said, 'I need to tell you what's going on, you're going to see a report come out,'" she told Newsmax TV. "The next words that came out of her mouth are words that are just so difficult to hear as a parent. She said, 'Demi overdosed.'"
De La Garza admitted to the outlet that she wasn't sure if her daughter had survived.
"I was in shock. I didn't know what to say. It was just something that I just never expected to hear as a parent about any of my kids. I hesitated to ask, but I had to ask her ... 'Is she okay?' And she stopped for a second, and she said, 'She's conscious but she's not talking.' I knew at that point that we were in trouble."
According to De La Garza, Lovato — who has been staying out of the public eye — is doing much better.
"She's happy, she's healthy, she's working on her sobriety and she's getting the help she needs, and that in itself encourages me about her future, and the future of our family."
Just one month before her overdose, Lovato released her song "Sober," in which she admitted she had broken her sobriety after six years.
"Mama, I'm so sorry, I'm not sober anymore," the star sang in the emotional track.
"I have always been transparent about my journey with addiction. What I’ve learned is that this illness is not something disappears or fades with time. It is something I must continue to overcome and have not done yet."
The "Tell Me You Love Me" singer added:
"I now need time to heal and focus on my sobriety and road to recovery. The love you have all shown me will never be forgotten and I look forward to the day where I can say I came out on the other side."
If you are struggling with substance abuse, please call the SAMHSA National Helpline at 1-800-662-4357 for free and confidential information.