What Causes Persistent Pain In Right Leg?

I have a lot of pain in my right leg there have been treating me for rls now it is getting worse and the pain is more oftern in the day time now has well has night time. I wear a fentenal patch 50 mg and change it every other day and still have the pain the only thing that gives shirt relief is roxescodein 15mg. If I drive for more than 20 min. I start getting the pain right leg calf upper thigh and the right side of butt