Jessica Simpson is so devoted to Dallas Cowboys quarterback Tony Romo that she changed cell phone number and e-mail address to cut off any potential communication from her exes.

"I don't want anybody that's been in my life [before] in my life anymore," she tells People magazine. "I don't even want them to have any way of contacting me."

Romo, 28, hasn't done the same, but Simpson, 28, doesn't mind.

"I'm not a jealous girlfriend," she says.

As for her relationship with John Mayer — which began in 2006 and ended last summer — Simpson says she had to "regain self-esteem and self-value" when it was over.

She also says Romo is her "perfect guy."

"I just told him today, 'You're the love of my life,'" she tells People. "I don't really ever say that to anybody."

Simpson also co-wrote a song for Romo called "You're My Sunday," which is featured on her new country album, "Do You Know" (out Sept. 9).

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