Yeah DM is diabetes mellitus.
Many diabetics end up in kidney failure.
There are 5 stages of kidney function, 5 being the worst. I don't know why you have it or if you are on the right meds -- those are questions you should ask your doctor. Polycystic kidney disease (PKD) is usually diagnosed by the presence of multiple cysts on BOTH kidneys as well as a family history of the disease (it is genetic). As people age, they tend to get harmless cysts but even these can grow large enough to put pressure on the rib cage or a nerve and cause pain. Pain is a common symptom of PKD.
I hope this helps. You should write down your questions and call your doctor. I know I don't always think of everything to ask right away.
By the way, I'm assuming that DM is diabetes. Let me know if I'm wrong and if so, I apologize.