Mel Greig endured a global backlash after Indian-born Jacintha Saldanha killed herself in late 2012 after transferring the prank call to staff caring for Prince William's pregnant wife Kate.
Greig and 2Day FM co-host Michael Christian had posed as Queen Elizabeth II and Prince Charles on the phone and were able to get details of her condition on air.
Saldanha left a note blaming Greig and Christian for her death.
During an interview with Channel Seven that aired Sunday night, a tearful Greig said she felt ashamed and as if she had been living a "stranger's life" since the prank call.
"You're meeting a Mel that has no confidence, a Mel that's so lost with her life, a Mel that feels so much blame and so much guilt nine months down the track. This Mel's depressed," she said.
The interview was filmed last September but only went to air on Sunday owing to legal reasons, the broadcaster said.
Greig said the Saldanha family was always on her mind.
"I just want them to see that I'm sorry because I care so much about Jacintha and what she did."
Greig, who resigned and sued her employer over workplace safety, revealed the fallout had an enormous impact on her family, including death threats.
"They would ring my mum and say 'eye for an eye you need to die because she died'. There was so many horrible phone calls," she said.
"Dad was rushed to hospital because of the stress and I thought 'oh great, now I've killed my dad, too'."
Greig, who is due to give evidence at the inquest into Saldanha's death when it resumes in London at a date yet to be confirmed, said she never wanted to go through with the call.
"I should have tried harder not to let that prank call air. It never should have aired," she said.
During her workplace lawsuit against employer Southern Cross Austereo, Greig won a public concession that she had not been responsible for broadcasting the call and had suggested it be edited before being aired.
She has not worked again since quitting, while Christian moved to another radio station.