Infection in Kidney. Other problems.

My mother Aged 58, diabetic patient was suffering from fever for almost 1.5 months. Test reflected that she was having some blood infection and with medication that has also gone. But after few days again she started to have fever and shivering. She also started pain in her back in one side and test shown that her creatinine and Urea level is high. CT scan doesn't reflected anything but blood culture is showing infection in her one kidney. She is on antibiotics through veins twice a day and initially she started to vomit after medication. Now she has become weak and getting itching all over her body. She has lost food appetite. Please suggest future course of action and this antibiotics course has only reduced her pain nothing more than that. As mentioned above she has started to develop some other problems.