Jessica Simpson’s bizarre behavior has pushed her marriage to former NFL star Eric Johnson to the brink of collapse. Sources claimed the couple have gone long periods of time without seeing each other, despite being married for 10 years and sharing three children together. Now, the pair face divorce rumors as Simpson’s behavior is said to have created more tension between them, RadarOnline.com can reveal. Simpson, 44, and Johnson, 45, spent more time apart after the I Wanna Love You Forever singer moved – by herself – to Nashville, Tennessee, to revive her music career. Meanwhile, her husband …