What Does Consistent With Moderate Chronic Kidney Disease Indicate?

I was a kidney donor a year ago. My latest readings for creatinine was 110 and GFR was 43. The lab report said consistent with moderate chronic kidney disease . Is this a normal reading for a person with one kidney? If not what should I be doing to protect my kidney? I keep protein and salt to a minimum, drink at least 4 glasses of water daily as well as 3 glasses of milk. Helen