Sir Elton John should now be dead from Aids like his friends Freddie Mercury or Rock Hudson, he said on Monday. For years he was addicted to drugs and drink and put himself at high risk of contracting HIV by his behaviour.

Telling the story of his descent into cocaine-fuelled chaos to the International Aids Conference in Washington DC, he said: "This young man hit absolute rock bottom. His life was a mess, he was spiralling out of control. He should have died. To be honest, he nearly did."

John, who started his own foundation to help people with HIV 20 years ago and has written a book about it (Love is the Cure), was speaking for the first time at the conference, which takes place every two years. In a passionate speech that was greeted with huge enthusiasm and a standing ovation, he said he was rescued from the depths of his addiction by those who cared for him and has now been sober for 22 years.

"By all rights I shouldn't be here today," he said. "I should be dead – six foot under in a wooden box. I should have contracted HIV in the 1980s and died in the 1990s, just like [Queen lead singer] Freddie Mercury, just like [actor] Rock Hudson. Every day I wonder, how did I survive?"

His message, he said, was that everybody deserved the love and care he received. "Everyone deserves compassion. Everyone deserves dignity. Everyone, everyone, everyone deserves love. Why am I telling you this? Because the Aids disease is caused by a virus, but the Aids epidemic is not. The Aids epidemic is fuelled by stigma, violence and indifference."

Science and money would not be enough to beat the epidemic, he said: "We need love. If that word makes you a bit uneasy – if you associate it with Disney and schmaltz, let's call it something else." Compassion or kindness were two suggestions. But he added: "It's been three decades of this epidemic, and we have seen how human beings react when those around them become HIV positive."

Drug user and prostitutes were condemned and stigmatised for leading immoral lives. Aids orphans were abandoned in the streets and children were raped and abused. "It makes me feel sick to think of this indifference and hate," John said.

But there were also people who had been compassionate, among whom he included George W Bush for launching his $15 billion president's emergency fund for Aids relief (Pepfar). The US could easily end its own epidemic, which in Washington is as bad as in some African countries, if it chose, John said.

"America has shown so much love for those living with HIV and those living in the developing world. If this country wanted to end HIV infections at home it could do so in a heartbeat," he said. "All it takes is a bit more funding and a bit more understanding. All it takes is dialogue."

The scientific tools now available to end HIV would not end the epidemic unless they were rolled out to all the marginalised and stigmatised people of the world.

"Maybe you think I'm a bit naive. Maybe you think I'm off my rocker. But even if your dreams come true, even if we had a vaccine it is not enough ... Science can stop the disease, but science alone can't end the plague."