How do I relieve the pain caused by a L5 fracture with spondylosis?

Manual therapies. Osteopathic manipulative medicine (omm aka omt) combined with physical therapy, frequency specific microcurrent (find online), home exercise program prescribed by pt and good nutrition! Afterward you will have to keep up with the exercise part, esp the abdominal and core strengthening. Pilates might help with the maintenance part. Also consider feldenkrais for gentle muscular/spine alignment.
This will heal. Without surgery over 12 weeks. A back support and medication can help as a well as avoiding lifting, bending and twisting while you heal. Avoid prolonged sitting and standing. Walk to tolerance. Lying down will be you most comfortable position. Once healed, get into good lifestyle choices like not smoking, exercise regularly and stay trim.