Kian Egan was almost sent to hospital during his time on 'I'm A Celebrity'.
The former Westlife singer - who was crowned King of the Jungle on Sunday - lost 9lbs in camp and admits extreme exhaustion took its toll and left him bedridden for two days.
He said: "Being bedridden was really worrying. I knew I was hungry, but I had two days where I couldn't get out of bed.
"I was having weird head rushes whenever I stood up. It was horrible. It was way, way harder than I ever imagined."
Kian - who was offered a doctor's visit in camp and given the all-clear after a full check-up when the show ended - admitted being back in the real world is "really weird" but he was delighted to be reunited with wife Jodi Albert and experience some home comforts again.
He told the Daily Mirror newspaper: "It's really weird to be out in the real world. Being around people is strange. Being on flat ground makes a huge difference in your life.
"As soon as I got out, I couldn't wait to spend some quality time with Jodi and have a hot shower - and eat some normal food. I was also looking forward to having a few drinks.
"It's an emotional rollercoaster in there. I've got loads of stories I can now tell my grandkids."
And despite his struggles, Kian - who has 23-month-old son Koa with Jodi - insists the experience was the best thing he has ever done.
He added: "I'm on top of the world. I can't believe I'm the king of the jungle. It was the best three weeks in my life. It was unreal and life-changing. It's genuinely something you'll never forget."
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