Rest and hot fermentation.

Good u start with ice pack, now u can take hot fermentation with hot towel, and continue applying diclofenac spray for more 2 days,  Do few stretches for back now.

Now you can give hot water fomentation for 15-20 minutes twice a day for another 5days. You can use Volini gel or spray provided you are not allergic. Avoid prolonged standing or sitting activities. Avoid frequent bending and lifting weights. Avoid staircase climbing. You should do back stretching and strengthening exercises once the pain vanishes with proper guidance.

Stop the ice pack take Hot pack, after that apply the pain killer gel like omini or dynapar, take rest,

Use pain'relieving gel like volini gel or diclofenac gel Use hot water bag three times a day 10 min-15min. Avoid lifting heavy weight. Avoid forward bending. Avoid long sitting. Use pillow under your back while working.