A wealthy Florida chiropractor thought she was dating Mets ace Pedro Martinez, but the lovelorn back cracker wound up being scammed out of almost $1 million. Dr. Rhonda Schroeder says she was fleeced by Shirley Gordon, a career con woman who enlisted two male pals to pose as the superstar pitcher. Schroeder, 34, is suing the imprisoned grifter to get back some of the cash she splurged in an effort to keep her bogus boyfriend happy, the St. Petersburg Times reported yesterday. The phony romance started in January 2005 when Schroeder went on a date set up by Gordon with a man she believed to be Martinez, prosecutors said.