A Big Brother spokesperson confirmed earlier today that Kay had departed the show in the earlier hours of this morning (Tuesday).
They said in a short statement: "Kay decided to leave the Big Brother House in the early hours of this morning. The other Housemates are aware."
Appearing on Big Brother's Bit on The Side, Kay said of her exit: "Originally I came on the show to promote veganism. I think because of the editing process they pick the most intense, dramatic moments. I think my narrative was 'unstable vegan'.
"I came on the show with so many boundaries or blocks where I didn't want to have intimate conversations and I didn't want to let a lot of that out. I think everything started getting to me.
"I couldn't engage fully and then I started freaking out about the cameras... I was policing myself all the time, thinking how things would come across."
Insisting she wasn't acting in the house, Kay said: "I'm emotionally up and down. I've not laughed more than in that house. There's been so many amazing moments. But in the evening, everyone would have a drink and arguments with people.
"I just felt embarrassed... I was analysing everything so much. I just freaked out."
Kay's exit played out in tonight's highlights after a row with Lewis Flanagan. She told BB: "I can't be in this house with Lewis."
Kay reacted: "I'm not sleeping on anything. I'm sorry, no, I need to get out. I'm f**king done. This is becoming some sick game. I need to get out please.
"This is against my will. You are keeping me in a place with people who aren't stable. He won't leave me alone."
Kay eventually returned to the house for one last time before packing her bags and leaving for good.
Big Brother 2018 airs Sunday-Fridays night at 10PM on Channel 5.