How To Treat Extra Cartilage Mediated Protruded Left Rib With High Activity And Heavy Breathing?

Hi, my lower left rib protrudes more than my right and causes severe pain, the older I get the worse it gets. It s a daily pain I live with and causes me constant trouble, if bothered too much it will swell also high activity, breathing heavy, and menstrual cramps hurt my rib. I ve been to doctors and they say it s extra cartilage.. But that it shouldn t hurt me. Is there anything else it could be?