Do you know WHY your lower back hurts? Did you injure yourself by lifting something? Did you fall? Do you have a pre-existing back problem like arthritis? I am not a doctor and cannot possibly advise you on taking care of your back. It could be a simple muscle strain or it could be something much more serious. I strongly advise you see your doctor as soon as possible as only he/she can diagnose the problem and offer the correct treatment.
I hope you feel better soon.
RubyWitch