Meghan Trainor fell into "the dark zone of deep thoughts" when she was forced to undergo vocal cord surgery.
The 26-year-old singer went under the knife for vocal surgery in 2016 for a second time after previously having a haemorrhaged vocal cord repaired in 2015, and has now said she battled with feelings of depression following the surgery, as she was worried she'd lose the ability to sing.
Speaking to Happiful magazine, she said: "I thought, 'It's over, I'm not going to sing ever again.' I went full dive into the dark zone of deep thoughts."
Meghan - who is married to 'Spy Kids' actor Daryl Sabara - previously detailed her battle with anxiety and depression in 2018, when she said she was left feeling "alone" and "terrified" as a result of her surgery.
She explained: "When I had an episode it would last for three days. I was crippled and had this pain. Eventually I was going to doctors, psychologists and therapists and I was like, 'My back feels like someone has a flame to it, I'm not sure if I'm going crazy.' And I'm feeling like I'm crazy, losing my mind.
"I remember standing in [US pharmacy] CVS with my friend in line and I saw the whole back row behind her move, when she didn't.
"You know, moments like that I had, dissociation with your body and you think you're schizophrenic - you're seeing things.
"I was sitting in my bathroom and the lights turned yellow. In those moments, you're terrified, you feel alone.
"You feel like there's something wrong with you and you're embarrassed to talk about it. No one can help you. It's your brain. It's chemicals."
The 'Dear Future Husband' hitmaker has been seeking professional help since her mental health struggle, and in 2018 said she was still in therapy, but was feeling much better.
She added: "The hardest part is when you're in the middle of it and truly believe there is no way this will ever end - 'I'm going to be stuck like this for ever' - and I believed that, until I slowed down with my anxiety and it stopped happening 24 hours a day.
"It was only like an hour. I was like, 'Wow, I have some control now.' Your brain is another person and you have to have a relationship with it.
"It took months - I'm still in therapy. I would see my therapist once a week and I started working out a lot and that really helped me.
"I take a lot of vitamins - I love Bulletproof vitamins. They've even got stuff for your eyes. I drank a gallon of water a day, sometimes more, for months now."