The 28-year-old star spoke with heartbreaking honesty about the the miscarriage she endured when she was six months pregnant, and her subsequent battle with septicemia.
"It was horrendous and something I would not wish on my worst enemy," Lily told The Sun on Sunday. "It's something that I still haven't dealt with, I never will get over it.
"…I held my child and it was really horrific and painful — one of the hardest things that can happen to a person. I was overwhelmed by what an incredibly unlucky thing it was to happen. But I had this man standing by my side, who I knew was going to be with me for the rest of my life."
Days after the miscarriage, Lily was rushed to hospital with blood poisoning, but said that she was so "numb" she didn't worry about the consequences.
"I nearly died," she said. "But I was numb and I didn't care. I'd just lost my baby and that is a reflection of how numb I was."
The singer is now a mum to Ethel, two, and 15-month-old Marnie, but she said she still has special ways to remember her son.
"I just think that he's a part of my eldest, really. If he hadn't died, it wouldn't have physically been possible for our eldest to be alive because I got pregnant with her so quickly.