The 25-year-old singer - who lost her first child with boyfriend Sam Cooper when she was six months pregnant last November - admitted the tragedy has changed her as a person and she has struggled to come to terms with what happened
She said: "It was a really long battle - and I think that kind of thing changes a person."
The `Smile` hitmaker has also spoke out about her struggle with eating disorder bulimia, confessing she used to make herself vomit after meals.
Speaking on new three-part Channel 4 TV show `LilyAllen: >From Riches To Rags`, she explained: "I used to vomit after meals. It-s not something I`m proud of. But, I tell you what, a lot of people came up to me telling me how great I looked and I`d be on the cover of every magazine.
"I thought I looked good and it was great to be able to try on clothes and feel a million dollars. But I wasn`t happy, I really wasn`t. I would love to be the skinniest person in the world but I can`t do that without being unhappy - I like food." Lily is on a self-imposed break from the music industry and admits the thought of being a pop star in 25 years` time is her "idea of hell".
She added: "People who are famous and successful and live in this mad world tend to die really early, or kill themselves or die in a drugs overdose. I`d rather not so I figure I will go and eat.
"My idea of hell would be doing this in 25 years` time. I don`t want to be like Madonna - look at her, she`s mental. No offence but that is not what drives me. I want to get married and have kids and make sandwiches cutting the crusts off."