She said she saw herself like an alien while experiencing the skin condition and felt "more disconnected from myself than I think I ever had".
Speaking at the Women in the World conference, Delevingne said she reached a turning point and that "I wanted someone to go 'you need to take a break, you need to look after yourself'. No-one did."
"I eventually said no and I eventually took a break. I took the advice of Kate Moss who picked me up off the floor passed out.
"I started writing - writing is something that really saved my life. I would read what I had written and it would be like someone else was speaking to me. It was a very strange experience.
"Then after that I found yoga, which was a huge thing for me.
"I was chanting and I got so angry with myself, and I broke through something and I burst into tears which I hadn't done in years."
Delevingne also shared a poem that she had written a year ago during a bout of depression.
She read out loud: "Who am I, who am I trying to be? Not myself, anyone but myself.
"Empty beyond the point of emptiness, full to the brim of fake confidence.
"The show must go on, it will never stop. The show must not go on, but I know it will."
Ending with advice for the audience of young women, Delevingne said: "My message has always been to love yourself, to embrace your flaws.
"The cracks within us are the beautiful parts that need to have light shone on them."
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.
- PAA
