What could cause these symptoms: pale stool, yellow skin, flank pain, acid in mouth, and more urination than usual?

Jaundice? Pale stool, yellow skin, & dark-colored urination suggests biliary obstruction--due perhaps to a gallstone in bile duct &/or from pancreatic inflammation. Consider significant liver disease (viral, familial, medication or alcohol-related, budd-chiari etc). Regardless of cause, please don't wait longer to get now a formal physical exam, appropriate lab studies, & if necessary medication or surgery.