Constant Lower Back Pain Radiating From Buttocks To Heels, Aggravates On Heavy Lifting, No Relief With Exercise. Solution?

Good Morning Sir, Iam Naresh, Age:26yrs, from Khammam, Andra Pradesh. A job holder have no physical hard work. Am suffering Lower Back Pain since three months. As i know lifted more weight causes this pain. Earlier Pain started at right buttock and shifting to left to right day by day. I Consulted Dr.Murali,MD., D.M.( Neurology ),@Khammam. He examined me and replied that it is a disc prolapsed @SLRT45degrees, it is first time na, so am not suggesting MRI and do the small excersize daily you l get relief. But I dont get any relief. Pain some times passes from buttock to leg heal when long sitting. I can walk freely, Can sit & Stand without any help any where but cannot bend forward as like as my earlier days. One of my friend is a Physiotherapist examined me and told me it is look like disc degenaration, or Sciatica . Please reply me and suggest me Sir. What I Have To DO... Naresh.