I also had (have) a pretty bad invasion of candida in one of my kidneys as well. The kidney is enlarged as per an ultrasound, and swollen and painful (although much less nowadays). It came after a severe candida gut infection for over a year.
One thing that has helped ease the kidney pain is d mannose. It's a Sugar that carries planktonic Candida out of the bladder. Also Nature's Way kidney bladder formula helped me greatly as well.