After the wild years of all-night fun, Florence Welch found a calmer way to live. She talks to Eva Wiseman about the "magic energy" that drives her and how she finally learns to make sense of herself.

There was a time when Florence Welch's voice was as inevitable as the siren of an ambulance. "You have love, youuuuu..." He was blasting out of car windows, shooting over sporting fixtures, echoing through Primark. And then, just as quickly, he disappeared.

Now 31, her hair less roaring fire, a softer sunset, Florence Welch is a quieter woman than the spinning girl behind number one's three albums who headed Glastonbury in a silver suit. Today, taking off her jewellery so as not to stab the tape recorder, she looks like Lady of Shalott in blue jeans. It was during this whole period when Welch heard that every time she left home she started to crack a little.

"That's when drinking and partying exploded as a way of hiding from him. I was drunk a lot, on a very dirty martini - my way of drinking three shots at a time. "I was never interested," and she laughs, bitterly, "a nice glass of wine." She says that sentence like it's an urban myth. She always liked parties. It was in the toilets of a London nightclub, in 2006, that she interrogated in front of her current manager, becoming Florence and Machine and breaking America three years later. She rarely slept during this period. When she came home after a two-day party, she was always in trouble. She was getting text messages, usually "Where RU?" "I'm not sure, but I'm wearing someone else's clothes..." The funny thing was, I didn't want to come downstairs. I always thought something picked me up and threw me around the different rooms and houses and then "boom!" She throws her arms out theatrically. "It happened every time, and every time it was shocking."

But the music came anyway, these huge bloody songs about love and loss - director Greta Gerwig described them to Welch as "the deepest, darkest well of pain, and then you just throw a big party there and invite everyone. This makes Gerwig cry, she admitted, uncontrollably. It took some time to sound - it wasn't until she started making music with another young woman, Isia Summers, that they appeared with the single Dog Days Are Over, a huge kate Bush-ian snarl pop song that came to define her. Until then she worked with older male producers. "And there was an unconscious postponement, a prejudice that was rooted." Four albums, she's still making music in the same controlled, "feminine" way, except she knows when to take it out today. "When it's too... Florencey?" I nod and then stop, for fear of being rude.

Approaching the tenth anniversary of this career, which quickly became very big, she decided to sober up. "When I realized I could perform without booze, it was an apparition." There is discomfort and rage, and the moment they meet is the moment you open up. You're free."

She's always felt absolved on stage, she says. Nobody was angry with her up there. It was her life outside the stage that she had to work on. Up there she would climb the scaffolding, holding her hand, jumping into the crowd and ripping off the mountain when she was sweating. After these nights, it's hard for her to get back on the ground. Everything, as she explains, starts to take on a magical meaning. There will be moments - sitting for example in the room of a friend watching TV - when, deprived of sleep and sober, she suddenly wakes up. "The mundane moments become incredibly deep. Spectacle, transcendence, then sitting and watching TV - everything can coexist, and the mundane makes it magical. Maybe I'm trying to stick to the normal. Maybe because being on stage has become normal, the pockets of peace seem really wild. But I value them."

So she stopped drinking and started living, and last night she saw a whole new series of Kimmy Schmidt's The Constant. "I think I've reached the bottom of Netflix." And although her life is calmer, her work has become louder. "Before, I thought I was running on the engine of chaos, but the more calm I am, the more work I can give. I can take care of things I've never been able to do before."

Florence likes to cheat. She does it with a blue pen, writing what she calls the little "weights of truth about herself," making sure she doesn't show them to anyone. "All right, it's just us..." And it was as one of them that Hunger, the first single from her new album, High As Hope, began. The first line is, "At 17, I started starving. "This is the first time I can write it down on paper," she whispers. "I thought love was in drugs," continues the song, "but the more I took, the more it took." And I could never get enough. I thought love was on stage. You give yourself to strangers, you don't have to be afraid. "But now I realize that this nugget of uncertainty and loneliness is a human experience. The big problems are there, however you take care of them." She suddenly giggles. "The strangest thing is that whenever you say it, other people say, "I feel the same way."

She was terrified to talk about her eating disorder for the first time. Not just talking - singing. Her sister was surprised. "You couldn't admit it for years, and now you put it in a pop song?" But terror meant, as Florence says, that she had to do it.

See also: Florence And The Machine lyrics