Thanks for asking a question. With right cost-phrenic injury there could be several other causes of your pain. Most common would be soft tissue injury to the muscles. Treatment would be similar to what you have already been trying. In addition to the muscle injury could be increasing muscle spasms which would gradually increase with time. Treatment again would be local heat or ice and muscle relaxants along with local massage therapy and physical therapy. Deeper injuries could be fractured lower rib or kidney contusion. Further testing would need to be done including x rays urinalysis. I would recommend seeing your primary care doctor to do further testing and treatment