Winehouse met Reed while he was dating the late designer at a 2006 party in Chelsea. Reed described the singer, who passed away last month at her Camden home, as a "beautiful human being".
"Yes, she was an addict with a serious problem but she was also the most beautiful human being," he told the Mail on Sunday.
"She had so much to give and she looked so lovely and normal standing there in her pyjamas without all her hair and make-up on. That was the real Amy.
"She had an old head on young shoulders and was very kind and caring. Some of us used to jokingly call her Mum because she was always looking after people. It's such a shame how her life ended. I miss Amy so much."
Reed explained that her boyfriend Reg Traviss helped persuade her to return to rehab and move on from her ex-husband Blake Fielder-Civil.
"I don't know if Amy was ever going to get Blake out of her heart, but I think she managed to shelve him. When I asked her if she was happy, she said, 'Happy's a big word but I'm getting there'. She said that things with Reg were good and that he was a kind and wonderful man. She seemed to be in a better place."
He revealed that she did not get along with Lee Alexander McQueen, who committed suicide in 2010.
"She and Lee didn't get on. Lee had offended her at the party where I first met her and Amy never forgave him.
"When he sent her a dress to say sorry she put it on the barbecue. She also spat on one of his dresses at Selfridges, which she had to pay for because she had soiled it. At first she refused, then she just said, 'Fine – but tell Alexander McQueen I ruined his dress'."
Amy Winehouse's boyfriend Reg Traviss is said to be "in a really bad way" since the singer's death.
> Amy Winehouse 'fell off the wagon' before her death
Watch the video for Amy Winehouse's single 'Tears Dry On Their Own' below: