The Northern Irish singer was just 16 when she auditioned for the ITV show, eventually coming fifth in the talent competition.
She told ITV’s Loose Women: “I moved to Sheffield on my own and I was 17 and in those days life was so hectic and it was amazing but at the end of the day, when you get home you’re on your own in an apartment in a different country where you know nobody, so it was very isolating and when I was in social situations I did turn to alcohol to give me a bit of a confidence boost.
“I would definitely say at about 18 I had a definite problem.”
Asked how she knew she had an issue, Devlin said it was because of a “failed suicide attempt”, adding: “I don’t know the exact moment when it got really dark but I pretty much just woke up one day with a bottle of gin under my pillow.
“Every day before going to work I would have to get drunk, at night I would have to get drunk, it really quickly went very downhill for me.”
Asked if her family knew about her attempt to take her own life, Devlin said: “My family didn’t know at the time and most of them were never planned.
“My poor mum was always just waiting on that phone call to find out when I finally was gone.
“I love her to pieces and I’m so glad every day that I’m not causing her the same pain.”
Devlin said she was compelled to drink in social situations by voices in her head that told her: ‘They don’t even like you, you need to go home, they are just doing this out of pity.’
Asked how she got sober, she said: “It wasn’t really my choice, I tried loads of times to get sober and nothing was really working but my mum flew over to help me out because I had gone missing for three days again.
“She came and walked me to a doctor’s office, walked me to this clinic where they try to get people sober and they had no slots left so somebody slipped me a card for AA and that is when I went and it just changed my life. It was like the first day of the rest of my life."
Devlin competed on the eighth season of the show in 2011, and released her debut album Hide and Seek in 2013 following her appearance. She is currently promoting her new album Confessional.
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Additional reporting by Press Association