By Debra Lewis Boothman Marisa Laudadio
April 18, 2011 12:00 PM

Bobby Brown smiles as his 22-month-old son Cassius tumbles at a children’s gym near their home in California’s San Fernando Valley. Blending in with the other parents, the R&B star cherishes his daddy-and-me time. “When I used to get high, I wasn’t there for my older kids,” says the father of five. “I always had a drink in my hand or disappeared.”

His life is different now. No more DUI arrests, jail time or cocaine and heroin, which drove his absences and out-of-control behavior. And it’s been four years since his divorce from Whitney Houston, who has admitted to her own struggles with cocaine. Watching scenes from their tumultuous marriage on his 2005 reality show Being Bobby Brown “was partly why I got clean,” says Brown, 42, who adds that he has been drug free for six years but still drinks. “I saw exactly what I didn’t want to see about myself.”

And certainly not what he wants to see about his kids. But last month, the National Enquirer published shocking photos of his daughter with Houston, Bobbi Kristina, 18, appearing to snort cocaine, leaving many wondering if she was carrying on the family’s troubled legacy. No way, says Brown. “She’s a good girl,” he says. “She knows right from wrong.” After the photos surfaced, he called Houston (“Me and Whitney are friends, but we are raising a daughter under her care,” he says)-and Bobbi, who claimed it was a joke and that a vindictive ex set her up. “It was a game they were playing,” Brown says, dismissing any suggestion she was spinning a tale. “She was hanging around some bad people and isn’t around them now. I trust my baby.” (She tweeted the same explanation, denying drug use and rehab rumors.) When pressed on why she’d kid about-of all things-drugs, Brown shuts down: “I don’t know. I’m protecting my daughter.”

While he publicly stands by Bobbi, Brown is privately “devastated,” says a close family source. “He and Whitney both love Bobbi, but she’s been living like an adult for years,” says the source. “She does what she wants. No one is really around to guide her.”

Brown says he has tried to provide Bobbi and his older kids (Landon, 24, La’Princia, 21, and Bobby Jr., 19) with that guidance using his past as a map of what not to do. “I had to explain what was in the papers about me and that what I did was wrong,” says Brown, who found fame at 14 with New Edition. “They saw what I went through. They’re smarter than I am. They know better.” Landon, a self-proclaimed high school “troublemaker,” says his dad’s hard-won lessons “have changed my life for the better.” He adds that Brown, though “fun-loving and energetic,” also insisted on curfews and good manners. Says La’Princia: “What’s important is he’s trying to improve. He’s changed his life a great deal in a small amount of time.”

In truth, the singer didn’t think he’d make it this far. “All the things I’ve done and been through, I never thought I’d reach 40,” says Brown, who was shot and stabbed growing up in Boston and later had a mild heart attack and stroke he says were a result of his drug abuse. He got clean after his sister Bethy, sober for 10 years, died from lung cancer in 2003. “I had just gotten out of jail [in 2004 for DUI probation violations] and was sick and tired of being sick and tired,” he says. “I did drugs because I was lonely and thought no one cared for me. I take full responsibility for everything I’ve done. I’m just grateful to be where I am now.”

And thrilled at where he’s headed: After five years of what he calls a “perfect relationship,” he plans to wed Alicia Etheredge, 37, his manager and mom of their son Cassius. The couple love dancing and karaoke, but just as important, Etheredge knows what triggers his demons. “Silence is a big sign, or when he gets depressed,” she says. “Family therapy is a great support. We do it all: meditation, yoga, self-help books, prayer, church and daily affirmations. It can get difficult, but he doesn’t ever want to be where he was again.” Adds Brown: “She makes me want to live.”

So he’d like to kick his pack-a-day smoking habit and cut down on alcohol, but he has no regrets. “My past made me the man I am now,” says Brown, whose first studio album in almost 14 years, The Masterpiece, drops in May. “I had to grow. I got my passion back for music, for loving myself. I’m a better person, so I can be a better partner and father.” His one wish: for his kids to reach his success without his failures. “They are my support system, my everything,” says Brown. “Without them, I don’t know where I’d be.”