Houston's new album went straight to number one in the US
Whitney Houston has said in her first major interview for seven years that she is drug-free, but faces a daily struggle to stay clean.
The singer admitted to Oprah Winfrey: "Don't think I don't have desires for it," and said that she occasionally drinks alcohol.
The star added that she has to "pray it away" when she feels vulnerable and was taking it "one day at a time".
Part two of Houston's interview with Winfrey aired in the US on Tuesday.
The 46-year-old, who released her comeback album I Look To You a fortnight ago, said music producer Clive Davis persuaded her to return to the recording studio.
"He told me I could do it," said Houston of the man who discovered her in the early 1980s.
"I was really afraid of going back into that world called the music industry, you know what I'm saying? But the music still lives in me. It's alive."
Her new album has topped the chart in the US and several other countries, while it is due out in the UK on 19 October.
In the first part of the interview which was screened on Monday, Houston said that her mother saved her from drug addiction by forcing her into rehab.
She also admitted smoking crack cocaine after denying it in a 2002 TV interview when she famously said "crack is wack".
The singer recounted the day her mother, Cissy Houston, turned up with a court injunction to force her into a drug treatment programme.
"She said, 'I'm not losing you to the world. I'm not losing you to Satan... I want my daughter back'," Houston recalled.
"She said 'either you do it my way or we'll go on TV and [say] you're gonna retire'."
Houston told Winfrey her then-husband, singer Bobby Brown, was also there.
"She said, 'if you move, Bobby, they're gonna take you down - don't you make one move'.
"And he stood there like he was scared."
Houston and Brown got married in 1992, divorcing 15 years later.
"He was my drug," she said. "I didn't do anything without him. I wasn't getting high by myself - it was me and him together. We were partners."
Houston now has custody of their daughter, Bobbi Kristina.
The second part of the Oprah interview will be shown in the US on Tuesday night
The singer, whose hits in the 1980s and 1990s included I Will Always Love You and I Wanna Dance With Somebody, said her drug use became "heavy" after her 1992 film The Bodyguard.
She told Winfrey she would smoke marijuana and crack cocaine at the same time.
"You put your marijuana, you lace it, you roll it up and you smoke it."
Brown, meanwhile, in an interview with CBS show The Insider - also shown on Monday - said their marriage "had its ups and downs and not many people understood it".
He said he had "used an awful lot" of drugs, particularly cocaine.
"I just think I was bored.
"I had just gotten married, and things [weren't] right and I turned to alcohol and drugs."