How Should Buttock, Hip And Leg Pain Be Treated?

Hi I have had a history of herniation of Lumbar 4.5 and s1 and I have aa leg length difference from birth congential hip. In the last 2 months I have difficulty sitting, upon standing in the morning I can bear wt for a while them I limp. I am taking advil for pain in my lt buttock hip and done the leg left. What kind of MD should I see?