07/31/2008 at 11:00 AM EDT
's country music career is just kicking off, but she already has plenty of material for songs about bad boys, heartbreak and a romantic Cowboy.
Promoting her new album
, Do You Know
, in the September issue of Elle
, Simpson, 28, says she has found happiness with her Dallas Cowboys quarterback boyfriend Tony Romo, 27, but admits the journey wasn't easy.
"I was going through a lot of pain," she says of life after her split from ex-husband Nick Lachey
, 34, in 2005. "I didn't try anything to change my life other than dating different types of guys and conforming to their worlds. I thought I had to be artsier, more intellectual."
One of those guys was John Mayer
, 30, who's now dating Jennifer Aniston
. The pair had a rocky year-long romance that ended last spring, but she has no hard feelings.
"John believed in the Jessica Simpson that's within," she tells the magazine. "He cherished our love. He helped make me the woman I am today. John is going to be an amazing man for someone, but I know that I was supposed to be with someone else."
Simpson says Romo is different from all of her exes. "Most of the guys I dated were captivated by my heart but they had different ways of trying to get to me. Tony understands me. He appreciates my talent. He's the first person I've spiritually connected with. I'm a girl that loves to be in love," she gushes. "I love love!"
Still, not all of her tunes are happy ones: "Remember That" is about an abusive relationship. "There's nothing on my album that you're gonna hear that I don't relate to or that I haven't experienced," she says. "Because the only way I know how to sing is from life experience. I don't want to talk about it, but I have definitely experienced abuse in a way that I would tell people to take their heart and run."
But things are good with Romo. While performing at a recent country music festival
, she dedicated her new song "You're My Sunday" to the QB, who is supportive of her new musical direction. "It's the cutest thing," she says. "He'll say, 'Jessica, 75 percent of the comments about your new single ['Come On Over'] are favorable.'"