In her most candid interview ever she began to sing to me, her exquisitely haunting voice filling the hotel room with her song Dark Road, sending chills down my spine. "You know when I'm really happy?" she said with disarming innocence. "It's when I'm alone doing very simple things; sitting on my bed with my laptop, blogging, or just getting information. That makes me happy. "Most nights after dinner with my kids I go upstairs to my room and lie down, blog on the internet or think. My room is my refuge, my sanctuary, the cool place I can go to in my life. It's not big but it's very special. It's very important to have that space. Like your front door. When I close it that's my world with the things I like, down to a shell I've picked up on a beach, with all my memories. "I eat dinner with my girls but don't cook. I have help. It's very important to have dinner with them - I like to feel engaged with my children, sit with them, listen to what they have to say. They make me smile, they're teenagers and very funny. "I don't have any family, my parents are dead and a lot of people have gone, and I'm divorced, so my family now is my girls and we're very close.
"My daughters aren't daunted by Annie Lennox, the icon. I'm their mother, they don't have to revere me. They know what I've done but they live with me, not Annie Lennox. Our relationship is unique to us and I protect that.
"They give me great joy, and apart from that it's just finding a raison d'etre in life. It wasn't always easy. I need to find meaning in my life to make me happy and that's been an ongoing struggle."
She has found meaning in South Africa, where she works with TAC, Treatment Action Campaign, which provides treatment for HIV sufferers. She recorded the anthem-like track, Sing, to help victims, with a chorus of top female artists including Madonna and Maria Carey, to be released at Body Shop outlets next week.
Bravely, Annie took her daughters to South Africa to see the terrible pandemic spreading among women and children with their own eyes. Dressed in smart black trousers and waistcoat, she poured out our tea and told me chokingly: "They met Aids orphans, and children who are HIV positive, and I think they understand their life is a huge privilege. I think they get it.
"I hope I'm not too hardcore about this because it's not fair to beat the drum too strongly with your children.
"I can't solve everything in the world but I can make my contribution. As a woman, mother and artist I feel drawn to this issue of Aids. Just as there were reformers and abolitionists in the slave trade, I think what I'm doing, Bob, Bono and others, makes us the modern-day reformers and abolitionists."
That said, Annie won't join the bandwagon of celebrities adopting an African child, like Angelina and Brad or Madonna and Guy. "Taking one or two children into my own household wouldn't work. I don't think my daughters would be comfortable with that," she admitted. "If people want to adopt children, that's fantastic. But it's not a solution for African people.
"Rather than them thinking celebrities take their children, I want to see South African children having lives in their own country and living beyond their fifth birthdays.
"I've seen terrible things there and it's shocking, but it's a reality and when I'm with children I identify with them, as a mother, and feel connected with them.
"The hard bit is leaving them. That's the bit that does me in. If I thought bringing one child home would solve the issue I would do it but it won't solve things."
Annie has had big loves and losses in her life with her Eurythmics partner Dave Stewart, her first husband, Radha Raman, and second husband, Israeli film producer Uri Fruchtmann, who left eight years ago.
Her scars are evident, and romantic love is a subject that clearly makes her feel very dark and anxious. "I've written a lot of songs about unrequited love, and for me love hasn't brought me the peace and fulfilment I expected from it," she said, her voice shaking.
"That hasn't been easy. And now I'm wondering about romantic love and whether the search for it is merely a red herring.
"It's a fine thing if you can get it but then, if you're a person like me, it will take you to a place of anxiety because it can never be sustained. We want it but when we get it, it's terrifying because you could be hurt, abandoned and it's actually a really risky place to be.
"I don't have a partner and obviously I think about romance but I'm seeing it differently than ever before. I always took it for granted.
"Now I think platonic love needs to be put in place first, that deep respect, caring, consideration and interest, but it's very hard to achieve.
"There's no need for me to ever get married again. Imagine living with someone every day! When I look at that now I think: 'How is it possible?' People get bored.
"For a man to be with Annie Lennox is not so simple. It's a hard call and do I really want someone to share the whole of my life?"
Annie Lennox, role model, musical heroine of a generation, is constantly battling against depression, anxiety and fear. While her strength and fierce determination is strikingly obvious, there is a fragility hovering about Annie that makes her seem edgy.
"No one said life was going to be easy," she said. "Anxiety, fear and negative thinking often paralyse me. Thinking about how anything could befall you is terrifying and I've felt incredibly fragile.
"But if you haunt yourself with this thought you just can't function, so you have to get beyond that and it's very challenging.
"Music has helped me a lot. It's a great strength. What I try to build in my children is a sense of optimism and security. Of course they will leave home eventually and that's great - they have to have their lives.
"I adore my daughters, I love them desperately but I've never lived through them. They will move on and become young women, which they already are.
"As long as we maintain our loving communication it will be all right and I'll carry on doing what I do in any case, whatever that's going to be."
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