Cat Power: 'I was just trying to stop myself jumping out of windows'

I moved around a lot growing up. The longest I stayed anywhere was when I lived with my grandmother in North Carolina – from when I was a baby until I was four and a half. Since then there has been a sense of being nomadic.

I didn't truly find my singing voice until recently. After The Greatest came out in 2006 people started calling me a "soul singer", but in my mind I didn't start really singing until years later.

Nelson Mandela was a huge presence in Atlanta, where I spent some time as a kid. They even have a statue of him in the park. When I went to Soweto as an adult in 1996 I had this idea that everything had changed. But to see the horror of what was happening in Johannesburg, of people being set on fire because they wanted their electricity turned on, I realised nothing had.

Patti Smith gave me life-saving advice. She told me: "It's your responsibility as an artist to stand up if you believe in something." I was overwhelmed by that. At the time I was just trying to keep myself alive and stop myself jumping out of windows.

We wouldn't have art and music if we all saw things the same. I've spent a lot of my life not fitting in. As a culture we forget that we are very different to each other.

I thought fame would let me change society. Around the mid-90s, when the Beastie Boys were doing their Dalai Lama thing, I thought I could help disenfranchised people find their voices. I still want to use my fame for good, but I don't know how to fix the world.

I used to lie about what I did. When a cab driver would ask me what I did for a living I'd say: "I'm a writer." I never thought I was a "good artist", like people are "good bartenders" or "good cleaning ladies" with efficiency and a work ethic. I didn't believe in myself.

I've looked death in the eye. The day after Sun [her 2012 album] came out I was in hospital with angioedema [a stress-induced and potentially fatal swelling in the body]. They told me they were going to put me in a coma to save my lungs. My friend came to visit and told me I'd made the Billboard Top 10 and all I could think was: "I don't want to die."

Songs can be destructive but helpful. Lyrics come from different places. Sometimes they come from a need, hope, memories or dreams, and sometimes they just come for no reason, from nowhere.

Everywhere I've been, I've seen the same type of people. It doesn't matter what language you speak or if you can drive a car or not. We all generally want the same thing: clean water, shelter and security for our families.

Cat Power plays the Brighton Festival on 18 May. For full details, go to brightonfestival.org