I am in constant pain and feeling very weak continuely with a fever at times. Is it kidney problem or something else ?

Hello I am a 37 year old female who is just home after having an ultrascan on my kidneys and they found a small white shadow on my right kidney. I have experienced several kidney infections over these past nine weeks the first which I was hospitalised with and it was named as Pyelonephritis and treated with IV antibiotics. I have had a further four antibiotics and am taking one at the minute. There are constant small amounts of blood in my urine. I am quite concerned as the doctor said this shadow does not bother him. I am in constant pain and feeling very weak continuely with a fever at times of every new infection. Now I am at loss as to why this is happening and would like to know your recommendation as to what steps to take next as I can no longer live like this or in this discomfort. Please help. Elizabeth xx