The "Nashville" star, in an interview on "Good Morning America," says she struggled with substance abuse, as well as a battle with postpartum depression after having her 7-year-old daughter, Kaya, saying, "I was on top of the world and I ruined it."

Hayden says at one point, her addiction to alcohol got so bad that she was hospitalized, suffering from jaundice, and the docs warned her liver was going to give out. Now, she says, trauma therapy and inpatient treatment over the last year has brought her to a place of peace ... but it's taken a lot of work.

As a childhood star, she says someone on her team gave her "happy pills" before she appeared on red carpets, "They were to make me peppy during interviews. I had no idea that this was not an appropriate thing, or what door that would open for me when it came to my addiction."

She says as the addiction got worse, she did have one place of sobriety, "My saving grace is that I couldn't be messy while on set and working ... But, things kept getting out of control [off set]. And, as I got older, the drugs and alcohol became something I almost couldn't live without."