ketamine does cause loss of kidney function. it also can be very dangerous by your abusing it in a long list of serious side effects.. i strongly recommend you seek medical help/rehab/NA. you have a long history of drug abuse. if you continue you will eventually destroy yourself. ketamine can even lead one to schizophrenia among many things. i'd google it to learn more of it's side effects. knowing the dangers of drug use will not stop you from using however.
so the questions arise...what are you trying to escape from? why do you feel you must be self destructive? what are the underlying causes of your addictions?
i feel you started this thread because you're concerned. if you are, think about commiting yourself to getting well. addictions lead to death. i know firsthand. i've lost many friends caused by addictions. they no longer are a part of the living. if you are concerned re your useage then seek help. if you aren't concerned it's russian roulette. do you wish to take that chance with your life? i hope not.
i hope you are reaching out for help.