JoJo opens up about struggle with drinking and depression

Some fans might remember singer JoJo best for her 2004 jam, "Leave (Get Out)," but the songstress is back and all grown up.

Armed with a catchy new single, and her first full-length album in 10 years -- titled "Mad Love" -- JoJo, now 25, is set for an epic comeback.

Of course, the last decade hasn't been easy, to say the least. JoJo went through a drawn-out legal battle with her previous, now-defunct record label, and also struggled with depression, drinking, and pressure she felt to lose weight at such a young age. ET recently sat down with JoJo, who candidly talked about what she's been through in the last 10 years since she put out her last album, 2006's "The High Road."

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"I've had many low points, honestly," JoJo tells ET's Katie Krause exclusively. "I thought, 'How can I come back from this, you know, too much time has passed.' I was depressed, I was drinking a lot because I wanted to get out of my mind. I'm being totally honest. ... I just wanted to feel good and get out of my mind and that was obviously trying to fill a hole that I had."

JoJo first topped the charts when she was 13 years old, and she says she was subsequently pressured to lose weight in her teenage years -- and sometimes took extreme measures. At one point, JoJo was eating only 500 calories a day and injecting herself with supplements in the hopes of shedding pounds fast.

"I just felt like, as a female artist, our bodies were up for debate," she explains. "I thought men could just have their opinion and tell me what I was supposed to look like. So, I was 18 and I was told that if I didn't look a certain way that they wouldn't put out my music. So, my music was already being dangled in front of me and they already were saying that, you know, things weren't gonna happen, so I was like, 'Oh, if this is gonna make my music come out, then OK.'"

"I was on shots," she reveals. "I was injecting myself with this thing from this dietician that makes it so you're not hungry, and it tricks your body into thinking you're pregnant, so then the food that it would give the baby, it ends up, like, expelling. ... I wasn't even done growing, necessarily, but because I wanted my career to move forward and I was so scared, I did it."

The experience definitely had some lasting consequences.

"It messed with me psychologically because I felt like, 'How can I maintain this?' after I got off of it," she admits. "How could I enjoy food? And it just made me feel like, 'Am I not good enough of a singer? Am I not special enough? Am I not pretty?' It made me question all that."

JoJo says she was eventually able to overcome her issues with the help of her fans, and also by releasing her music for free online. She's now signed to Atlantic Records.

"I had to sue twice. I spent all my time and money to get to the other side of it," JoJo comments. "But during that time, I was releasing mixtapes, I was maintaining my relationship with my fans -- which is everything to me -- and which really kept me somewhat sane."

Her new single, "F--k Apologies" featuring Wiz Khalifa, is all about radiating empowerment and confidence.

"I don't feel confident one thousand percent of the time, but oftentimes I write the songs that I need to hear, with the messages that I need to," she says. "I feel like, particularly as females, sometimes we apologize for taking up space ... for taking the moves that we need to make, whether we realize that we're being apologetic for it. So, it really is just about knowing who you are, digging who you are, not making excuses to make other people feel comfortable."

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And with time definitely comes more wisdom.

"My last album I was 15 [years old]-- so [now at] 25, of course I have a new perspective and a new appreciation for what it means to be able to live my dream," she says.

"Mad Love" hits shelves on Oct. 14.