Demi Lovato is a fighter.
The pop star's hospitalization on Tuesday is the latest setback in her ongoing struggle with substance abuse, which has spanned the better part of the last decade.
Following six proud years of sobriety, the "Sorry Not Sorry" singer revealed earlier this year that she'd fallen off the wagon, and got candid about her drug relapse and sobriety battle in an emotional new single, "Sober," released in June.
After it seemed like the singer had managed to reach a place of peace once again, the world was shocked on Tuesday when she was rushed to the hospital due to what sources tell ET was a drug overdose. Now, ET is going back to look at what led to her medical emergency and her personal struggles in recent months.
March 14 -- Six Years Sober
The 25-year-old singer took to Twitter to commemorate an important milestone in her ongoing sobriety journey, sharing with her fans that she's "just officially turned 6 years sober."
"So grateful for another year of joy, health and happiness. It IS possible," Lovato wrote, ending her tweet with a prayer hands emoji.
The post came just a week after she opened up in an interview with Billboard about how her experiences as a celebrity have presented some real challenges to her sobriety – especially her time at the 2016 Met Gala.
"I had a terrible experience," Lovato recalls. "This one celebrity was a complete b**ch and was miserable to be around. It was very cliquey. I remember being so uncomfortable that I wanted to drink."
To combat the temptation, Lovato left the event and headed straight to a 10 p.m. Alcoholics Anonymous meeting. She recalled, "I changed my clothes, but I still had my diamonds on -- millions of dollars of diamonds on in an AA meeting… And I related more to the homeless people in that meeting who struggled with the same struggles that I deal with than the people at the Met Gala."
April 2 - May 24 -- Lovato's Relapse
While news of the singer's relapse didn't surface until the release of "Sober," a source told ET in June that it occurred at some point in between the North American leg of her Tell Me You Love Me World Tour, which ended on April 2 in Newark, New Jersey, and the European leg, which started in Belfast, Ireland, on May 24.
"Demi relapsed and started drinking alcohol again," an additional source told ET.
April 10 -- South America Production Dates
Lovato announced that she had to cancel all three stops on the planned South American leg of her World Tour due to "unforeseen production issues."
"I’m absolutely heartbroken that I have to make this announcement today... due to production issues we have to move the South America #tellmeyoulovemetour dates," she tweeted. "Ecuador, Costa Rica, and Panama I’m devastated we had to remove those shows."
"Truly hate that we have to do this & we tried our best but there were some unforeseen production issues. If you’re unable to make the new dates we will give you a full refund," she continued in another post. "I’m so sorry. I promise it will be worth the wait & I hope to see you. I love you guys so much!"
The planned shows have not yet been officially rescheduled. The nature of the production issues was not elaborated upon.
May 2 & 3 -- Fractured Foot and Feuding Friends
During her tour hiatus, the singer revealed that she'd injured herself while on vacation. Lovato took to Instagram where she told fans, "Guess who fractured her foot walking down the stairs in Bali."
The injury followed a number of somewhat vague tweets in which she stated, "True colors are shown in chaos," and that she is "Grateful for those closest to me who have never left my side and love me for who I am."
Fans on Twitter speculated that the feud could have been with one of Lovato's old friends, who had reportedly taken to Facebook to slam the singer for not coming to her birthday.
While she didn't address her friend by name, Lovato later tweeted, "Do me a favor, stop existing in my life and then stop trying to get attention by publicly shading me knowing the reaction you’ll get from my fans."
June 1 -- Personal Growth
An optimistic-sounding Lovato took to Twitter, where she said she feels like she's "grown more in the past two months than I have in years."
"I feel like a new woman and I’m so grateful for my life today," she wrote.
June 3 -- Cryptic Q&A
The singer told her fans to ask her questions while she was bored, and while many of the exchanges were simply fun and quirky, one stood out as a true look into the singer's personal life.
When asked what was the "biggest lesson you learned this year," the singer responded, "You can’t always trust people who you once thought saved you."
While she didn't specify who it was what she felt betrayed by, Lovato posted another cryptic tweet a month later, on July 5, where she wrote, "Good luck on your blog." The remark led many of her diehard fans to believe she was shading Mike Bayer – a CAST Centers life coach who appeared with Lovato during an emotional interview on Dr. Phil earlier this year and who has also gone on tour with the pop star.
Bayer, who has previously been credited with helping Lovato get sober after her 2011 rehab stint, posted a video to Instagram that many fans thought was specifically aimed at Lovato, criticizing celebrities who "call themselves artists" so they have "an excuse to be late, or insincere, or rude, or unapologetic." Following the two posts, Lovato and Bayer both unfollowed each other on Twitter.
June 10 & 11 -- More Postponed Shows
Just 45 minutes before Lovato was supposed to take the stage at the O2 arena in London, England, the singer posted a lengthy statement to Twitter, explaining that she needed to postpone the show "due to being very, very sick and with swollen vocal chords."
The singer added, "If I go on tonight and injure my vocal chords anymore I could potentially have to cancel the rest of my tour. I'm so so so sorry to disappoint any of my fans… It breaks my heart to let you down."
The next day, the singer tweeted that she was "gutted" to have to postpone yet another show, this time at Arena Birmingham, due to her illness.
"I’ve never had to miss shows due to my vocal chords or being sick in my LIFE," she tweeted. "This seriously sucks.. haven’t left my hotel room in 2 days now. Sick, bored and bummed out."
June 21 -- Getting Real With "Sober"
The singer released the powerful single, in which she got very candid about her recent relapse and how it affected her.
Lovato revealed the new song via Instagram, with a video she captioned, "My truth... #sober out now."
"Call me when it's over 'cause I'm dying inside," she sings. "Wake me when the shakes are gone and the cold sweats disappear. Call me when it's over and my self has reappeared."
"Mama, I'm so sorry I'm not sober anymore," she continues in the chorus. "And Daddy, please forgive me for the drinks spilled on the floor. To the ones who never left me, we've been down this road before. I'm so sorry, I'm not sober anymore."
June 24 -- Crying in Concert
The troubled songstress had to fight through tears to perform "Sober" at a concert in Portugal. Lovato posted a video on Instagram of the performance at Rock in Rio Lisboa, a music festival in Lisbon, where she took to the stage in front of thousands to sing the intimate, vulnerable tune and her voice audibly cracked as she began to cry while singing about letting down her fans.
July 22 -- "Sober" at the State Fair
Two days before her hospitalization, Lovato joined longtime friend Iggy Azalea for a performance at the 2018 California Mid-State Fair in Paso Robles, California, where she appeared to be in high spirits.
An eyewitness who attended Lovato’s show told ET the singer “was in a great mood” and “was her normal enthusiastic Demi-self." However, the eyewitness said that at one point during the concert, just before singing the last verse of "Sober," Lovato said, "'F**k, I forgot the words' and walked offstage."
"It was an emotional song. She seemed to be almost in tears," the eyewitness shared. "I think it was because it was a new song and she was emotional. That is why she forgot the words. As a fan, that made her seem more human. We all make mistakes."
The eyewitness added that Lovato "didn’t seem under the influence" during the concert.
July 24 -- Hospitalization
Sources told ET that Lovato was transported to a Los Angeles area hospital where she is being treated for a drug overdose.
TMZ reports that the singer was administered Narcan -- an emergency treatment for opioid narcotic overdoses.
A rep for Lovato released a statement to ET hours after news of her hospitalization broke, confirming that the singer was conscious and responsive.
"Demi is awake and with her family, who want to express thanks to everyone for the love, prayers and support," her rep told ET in a statement hours after she was hospitalized. "Some of the information being reported is incorrect and they respectfully ask for privacy and not speculation as her health and recovery is the most important thing right now."
In the wake of her hospitalization, Fox announced they were pulling an episode of Beat Shazam, featuring Lovato as a guest star, that was supposed to air that same day. Additionally, her upcoming tour stop in Atlantic City, New Jersey, was cancelled.
For more on Lovato's hospitalization and health, watch the video below.
Demi Lovato 'Pushed Away People,' Was 'in a Dark Place' Before Overdose: Sources
Demi Lovato's Longtime Friends Nick and Joe Jonas Show Support After Her Overdose
Fans Emotionally React to Demi Lovato Hospitalization Following Drug Overdose