Carr said in the Facebook post that she had suffered depression since she was a teenager, and that clean eating and regular exercise usually helped to control the condition.
However, since a knee injury has prevented her from exercising, she had been falling back into "dark thoughts".
"Recently I've been feeling myself fall back into the black pit, usually I can pull myself out pretty quickly but it's happening more often and for longer periods of time," she wrote.
"I'm having horrible dark thoughts and dreams which become really upsetting. I'm craving more and more alcohol, fried and sugary foods. I'm moody, snapping and distancing myself from people."
The popular blogger, who posted the note below an image of herself about to get an MRI scan for her knee injury, said that she would be taking some more time for herself from now on.
"I'll be taking some quiet time to look into other coping mechanisms that could work for me at the moment, surround myself with love and positivity, avoid alcohol, clean up my eating and work on a few more easy going, stress free goals."
The highly personal post resonated with thousands of Facebook users, and has attracted over 370 comments.
"Well done for putting yourself out there and talking about it," wrote one commenter. "You've probably opened the doors for many others to invite a conversation about depression."
"You're very brave sharing this, I too went through something similar a few months ago," said another.
Carr urged anyone else who is struggling with depression to seek help.
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 (Palmerston North and Levin)
• Youthline: 0800 376 633
• Kidsline: 0800 543 754 (available 24/7)
• Whatsup: 0800 942 8787 (1pm to 11pm)
• Depression helpline: 0800 111 757 (available 24/7)
• Samaritans: 0800 726 666 (available 24/7)
If it is an emergency and you feel like you or someone else is at risk, call 111.