"To know that it wasn't fully his fault really was saddening to me," the singer says of her late dad's struggle

Demi Lovato is sharing the heartbreaking inspiration for her new song “Father.”

In a video series about the making of her album Confident, the 23 year old explains how she reacted when her dad, Patrick Lovato, died in June 2013.

“I was very conflicted when he passed because he was abusive,” explains Lovato. “He was mean, but he wanted to be a good person, and he wanted to have his family. When my mom married my stepdad, he still had this huge heart where he would say, ‘I’m so glad Eddie’s taking care of you and doing the job that I wish I could do.'”

Lovato, who has been vocal about suffering from bipolar disorder, says her dad endured a struggle of his own.

“He knew he wasn’t capable of raising a family, and it was because of his mental illness,” she says. “To know that it wasn’t fully his fault really was saddening to me. I wanted to write about it. I wanted to process it.”

Lovato has also taken action. Earlier this month, she fought for mental health reform in Washington, D.C., and late last year, she raised money for her Lovato Treatment Scholarship Program, which she started in memory of her dad.

The former Disney star’s personal music in the midst of a challenging year, during which her great-grandfather and dog died.

Throughout all her challenges, the pop star hasn’t wavered in her message about self-acceptance.

“It’s extremely important for me to even embrace my body and my sexuality with showing more skin – I think it’s great,” Lovato told PEOPLE prior to her recent nude photo shoot for Vanity Fair. “I went from being in a place where I was suffering from an eating disorder and hating every single inch of my body to now baring my legs and showing more skin in front of the whole world and being proud of my body instead of loathing it.”