Thank you for your question. Cervical rib is a congenital anomaly in which additional rib is present in the body. This extra rib compresses the nerves plexus, artery and vein causing thoracic outlet syndrome. Symptoms could be neck pain that radiates to shoulder, numbness. Usually, symptomatic treatments like pain killer, physiotherapy are advised by the doctors and surgical resection may be helpful in few cases. I would recommend that you consult a neurologist in this regard for a complete assessment of your situation and for appropriate treatment. Hope this helps.
Sounds like you have been diagnosed with TOS(Thoracic Outlet Syndrome). This etra rib can compress blood vessels and nerves causing problems. You should be following up with a Neurovascular Specialist if you have diagnosed with this.
Secondly, aren't you following up with the physician who diagnosed you? Any physician?