Colbey,
Unfortunately it sounds like you have a lot going on in your body. Diabetes is just an awful condition that has just so many nasty complications. I think your response to your neurologist when he recommended advil was great. Good job at being an advocate for yourself! Due to your complications from the DM, I think it would be a fantastic idea to visit a pain management clinic. The specialist there should not only be up on the available pain meds and their uses but also what you, in particular can take with the stage three kidney disease!
Side note - The community I live in has only one of these clinics which is attached to the hospital I work in. This pain clinic is fantastic, along with the hospital so I might have a slightly skewed notion.
But in all honesty, since you haven't had any luck with your doctors idea of pain control and considering the amount of medications for pain you take compared to the amount of uncontrolled pain, a good next step for you could be a good pain clinic.
Good luck! I really hope you find a solution quickly.