My wife is ruining my credit

I divorced my wife in 2004. At the time I just wanted out. I agreed to just walk away. The house was financed in her name only, which made it easy. We also owned some land that I believed she paid off when she received an inheritance from her father after his death. I signed a quitclaim deed to take my name off the land's title. As you can probably already guess, she had not paid off the land and my name is on the mortgage. She has missed numerous payment over the last 5.5 years and my cr...