Suggest Treatment For Pain From Lower Back To Leg

Hi there, I'm in need of some assistance. I have a lot of pain in my mid lower back, goin down to my right leg. I can't walk correctly as it causes too much pain. This happened a couple of hours ago when I stood up and felt a sharpe snapping sensation. I have never had this or anything like this before, no back problems run in my family so I am concerned. If anyone can advise me I would be very greatfull, thanks, Kirsty x