I am sorry, but I do not know enough about that particular condition to give you good advice. I would suggest that you look for the forums that discuss renal problems in addition to my response.
MSK is a congenital condition that doesn't destroy the function of the kidney, and so a person with the condition would have a normal life expectancy. The fact that you are in pain concerns me, as it may mean that you have kidney stones-- which CAN lead to problems with kidney function.
It seems that you have two primary issues. The first is with the quality of the medical care that you are receiving; you may need to become a bit more aggressive in finding good doctors and advocating for yourself. You do deserve answers; maybe on your next visit you need to make it clear that you are not comfortable leaving the office until you have some questions answered. I suggest making a list of questions ahead of time, as the mind tends to go blank when an intimidating person stares at you.
The second issue deals with the type pain treatment that is appropriate for you. I recommend reading up on the subject of 'nonmalignant chronic pain', as that is where the controversy over your treatment will be centered. Some doctors will tell you to avoid pain medications, and others will prescribe them way too liberally.