By Aili Nahas
October 03, 2011 12:00 PM

It’s David Arquette’s 40th birthday and he’s spending the day in search of the perfect present for himself. Browsing at L.A.’s Golyester, the actor, known for his quirky bow ties and colorful suits, ponders a pair of his-and-hers ’70s-style tops printed with stars-potential costume pieces as he embarks upon the new season of Dancing with the Stars. “I love dancing,” he says of his gig on the hit ABC series. “It makes me feel good. And balance is a theme within dancing, and it’s been a theme for me: coming to terms with my issues and where I want to go with my life.”

Which is why-after a year of soul-searching since his separation from Courteney Cox and his subsequent spiral into alcohol abuse and rehab-the now sure-footed Arquette is stepping onto the dance floor. During the months that followed their split, which was announced last October, “My heart was shattered,” Arquette says. “It hurt so bad I didn’t know what to do. I couldn’t face the pain, so I used that as an excuse to act like a child and be really upset and rebellious.”

Arquette became a fixture on L.A.’s party scene, appearing haggard at clubs and placing TMI-filled calls to Howard Stern’s radio show. “It was part of self-loathing, which can get into your head and be completely dangerous,” he says now. “I would get drunk and run through traffic and do crazy stuff.” And things almost became far darker: “I would get so bummed out that I would have fantasies of just disappearing, thinking, ‘Well I have a daughter, but I’m in such pain right now that everyone would be better off if I just got out of here.’ Ultimately I knew that’s not what I wanted.”

Last winter, when his close friends, including Cox, staged an intervention, Arquette finally decided to get help. “I was ready. You have to be ready to want to change.” He entered a monthlong rehab program on Dec. 29 and says he has been sober ever since. Sobriety “isn’t a struggle really. I was using alcohol to avoid my emotions, to numb myself,” says Arquette. “I like to be accountable now, to be present and connected. I don’t ever want to drink again.”

With a new, healthy lease on life, Arquette has been tackling his other personal issues-and acknowledging his role in the sad crumble of his 11-year marriage to Cox, 47. “Nothing about this process has been easy,” he says. “It’s hard to ask the difficult questions and come to terms with your part in a relationship falling apart.” When Cox and Arquette started dating after meeting on the set of Scream in 1996, their relationship was surprising to many: She was the type-A glamour girl, he was the goofy charmer. Ultimately, says Arquette, those disparities were part of their undoing. “Courteney and I are very different people at heart,” he says. “As relationship partners, I’m not sure we’re the best match.”

Arquette attributes many of his personality quirks to a childhood spent on a Virginia commune with his siblings, actors Rosanna, 52, Richmond, 48, Patricia, 43, and Alexis, 42. “I had a dysfunctional family and I didn’t have a lot of boundaries. When I was in kindergarten, I learned curse words and I washed my own mouth out with soap,” he says. “I wanted boundaries, and that’s part of what I loved about my relationship with Courteney. But I wasn’t always true to myself.”

The future of their union remains unclear. “We’ll always be together, I just don’t know what will happen with our marriage,” he says. “There’s no romance there. We’re in the friend zone.” But Arquette has held on to his wedding ring, inscribed with the words “A Deal’s A Deal.” “I was so committed to that ring,” he says. “Taking it off was a big deal to me. But we still have a commitment, to being there for each other, to treating each other with respect.”

Even so, he’s preparing to move on. Is he dating again? “I’m just having fun,” Arquette says. “But I miss being in a relationship, being in love.” His most important relationship remains the one he has with his daughter Coco, 7. “She’s a really interesting combination of [Courteney and me] and then an incredible person on her own.”

Like a typical kid, Coco is often wary of Dad’s antics. “She gets embarrassed by me,” he says with a laugh. “If I sing or dance in public she’ll say, ‘Dad, no!’ I’m sure I’m going to embarrass her on Dancing.” But he didn’t. “David is amazing,” says Cox, after watching David’s Dancing premiere with Coco. “He had such grace and charm. I’m so proud of him.”

In addition to Arquette’s Dancing tangos and twirls, his plate is full. He plans to open an L.A. nightclub, has recently returned from a charity trip to Africa with Malaria No More and has three television projects in the works through his production company with Cox, Coquette Productions. “I’m a very fortunate person,” he says. “I never take that lightly.”

Especially now that he has turned the big 4-0. “If you look at a natural life span, I’m halfway through it,” he says. “Now I have this other half. What am I going to do with it? I hope I do really magical things.”