Suggest Treatment For Lower Back Pain

Hi doctor....

I am kapil and I am working in bpo. So I have to sit in my office for 8 hours continuously. 4 years back in my x-ray report there is Spondylolysis . But just 4 month back I have done another x_ray for my back but that time it was normal. So my doctor allow me to go to gym for exercises. Now these days I have lower back pain. Could you you please suggest what needs to be done.