LeAnn Rimes admitted to treatment facility for anxiety

Once a cheater, always a cheater?

The day after her 30th birthday on Aug. 28, LeAnn Rimes admitted herself into a 30-day inpatient treatment facility for anxiety. "She is simply there to learn and develop coping mechanisms," her rep said in a Aug. 30 statement.

At the root of Rimes' distress is an all-consuming obsession with husband Eddie Cibrian's wandering eye -- further{} fueled by cyberbullying she has suffered ever since the 2009 extramarital affair that began their romance.

"LeAnn has had major insecurity issues since she first got together with Eddie," explains a friend of the couple to Us Weekly. "She's been stressed about always being called a home-wrecker and also worried that Eddie is cheating on her. She's been on a downward spiral."