KIDNEY FAILURE!

i spent all day having tests at the vets, my mum didnt come and pick me up till 7pm and then the vet had a word with her which was not good news!...he told my mum that ive got kidney failure!....this is why ive been drinking loads and sometimes even weeing on my mums lap! and also why i keep loosing my balance and falling over, ive got to go on a low protein diet and have vitamin b supplements, im only 8 years old so why has this happened to me? and ive only been living with my mum for 2 years and she is devastated!....the vet told my mum that theres nothing they can do!...but my mum says she will make my life as best she can and i know she will as she loves me so much.