For The Past Few Months I Have Been Experiencing Lower

For the past few months i have been experiencing lower back pain . I also have stiffness everynow and then and its very painful to bend. Sometimes i can either lay in bed to rest or just try to walk up steps and my entire back will become so stiff i cant move and i get to where people have to help me walk or to get up. What could be causing all of this? I also have unexplained leg pain with burning and itching and it gets so bad that i cant drive at times. What could be causing all this pain and stiffness?