Harvey, who lost 12 kilograms during her time on the show, tells this week's edition of New Idea she has always struggled with low self-esteem and hates looking in the mirror.
"I've always been one of those people who has been insecure," she told NI.
"I don't rate myself as a hot person. I'm average."
Harvey said her weight gain over the years came from a combination of fertility drugs, anti-depressants, slow metabolism and eating the wrong things.
Her insecurities reached a tipping point earlier in the year.
"At the beginning of the year I was at my worst," she said. "We were in Mexico and I had to get into togs. I felt so gross and depressed and sort of just hit breaking point."
Despite not making it to the finals, Jay-Jay won praise for her outrageous routines on Dancing With the Stars which included dressing up like a saucy schoolteacher and a cheerleader.
But the outspoken DJ said she had learned how to hide her troubles in public despite her long history with depression and body image issues.
"In some ways I'm an actress because on the days I do feel terrible I know how to put it on. I don't want to bring the party down with my problems.
"You have to put on a brave face even when you're feeling horrible."
She told New Idea that she hoped that sharing her struggles publicly would empower others coping with depression.
"I have so much to be grateful for. I always say you have to look at all your positives. If you know what makes you happy, try to make that happen," she said.
"Despite everything I've been through, I always try to move forward and don't dwell on the past."
Where to get help:
• Lifeline: 0800 543 354 (available 24/7)
• Suicide Crisis Helpline: 0508 828 865 (0508 TAUTOKO) (available 24/7)
• Youth services: (06) 3555 906
• Youthline: 0800 376 633
• Kidsline: 0800 543 754 (4pm to 6pm weekdays)
• Whatsup: 0800 942 8787 (1pm to 11pm)
• The Word
• Depression helpline: 0800 111 757 (available 24/7)
• Rainbow Youth: (09) 376 4155
• CASPER Suicide Prevention
If it is an emergency and you feel like you or someone else is at risk, call 111.
- nzherald.co.nz
