The 25-year-old singer posted a video on Instagram of the performance at Rock in Rio Lisboa, a music festival in Lisbon, Portugal, where she took to the stage in front of thousands to perform the intimate, vulnerable "Sober." In the video, as she reaches lyrics that describe her letting her fans down, her voice visibly cracks as she fights back tears.
"And I'm sorry for the fans I lost, who watched me fall again," she sings, wavering. "I wanna be a role model, but I'm only human."
Lovato had a short message accompanying the Instagram video.
"Tonight I took the stage, a new person with a new life," she wrote. "Thank you to everyone who has supported me throughout this journey. It will never be forgotten ❤️ @rockinriolisboa."
Lovato is currently finishing up the second leg of her Tell Me You Love Me world tour. Two sources have told ET that Lovato's relapse occurred at some point in between the North American leg of her tour, which ended on April 2 in Newark, New Jersey, and her European leg, which started in Belfast, Ireland, on May 24.
That reported relapse is what led to the writing of "Sober."
The song has been widely praised for shining a light on addiction and relapse. Singer Iggy Azalea tweeted out her support, saying, "I’m proud of you for having the guts to reveal your truth to the world again. NOT. EASY.”
For a closer look at Lovato's reported recent relapse, watch the video below.