Your symptoms are typical of nerve pain brought on by a lumbar disc herniation. Use a solid but comfortable mattress that supports your back instead of strict bed rest on a very hard surface. If sleeping flat hurts, you can either lie on your side with a pillow between your knees or gently raise your legs. Complete immobility is not recommended; short, cautious position adjustments and mild leg movements are acceptable, but stay away from lifting, bending, and prolonged standing. If your pain is severe or not getting better, your doctor may recommend physiotherapy or other treatments, so heed their recommendations.