What Causes Severe Backache And Stiffness In The Shoulders?

My back has been killing me since I had my son. My back, neck, and shoulder gets stiff. My hands also get very stiff in my fingers mostly. At random times my hands will go numb as well as from the waist down. If I sit too long I lose feeling in my legs and when I m driving my hands stiffen up and my joints cramp. It s hard to take care of my son because it hurts so bad some days. My dr basically ignores me during the appointments. I was wondering if you could tell me what I should do? He prescribed me fibromyalgia meds without even testing me.