Heidi Range contracted blood poisoning after suffering an infection while breastfeeding.
The former Sugababes singer and her husband Alex Paratakis welcomed daughter Aurelia into the world in January, and the blonde beauty struggled to breastfeed.
She was eventually diagnosed with mastitis - where milk ducts become blocked and infected - by a midwife, but a health visitor then realised things were much more serious and she was rushed to hospital with Sepsis.
She said: "I was in so much pain, shivering and delirious, but I thought it was because I was so exhausted.
"It was only when the health visitor saw my symptoms and spotted a rash that she said, 'I think you've got sepsis, you need to get to hospital.' "
Tests confirmed the 34-year-old star had the life-threatening infection - which is contracted by just 1 per cent of mastitis sufferers - and she was put on a drip for four days to fight it.
But despite her serious problems, Heidi's main concern was for her daughter.
She told Britain's HELLO! magazine: "I looked at Aurelia and said to Alex, I'm so glad this is happening to me, not her."
The 'Push the Button' hitmaker continued trying to struggle through expressing milk and though it "upset" and "embarrassed" her to use formula, she eventually realised it was best for both herself and her daughter.
She said: "My lowest point was when Alex brought in a coffee. I put the expressing pump down to have a sip and the nurse snapped, 'And why aren't you pumping?'
"I was so upset. I felt embarrassed that I couldn't feed my baby and had to give her a bottle
"Alex said, 'You are sacrificing every aspect of what should be a lovely time for breastfeeding'.
"He was right. There's all this pressure on breastfeeding but sometimes it doesn't work out.
"We are all winging it, it's trial and error."