Suggest Remedy For Skin Ailments

For the past week and a half I have had intermittent left sided chest pains under my left breast and left sternocostal area on the left as well. I am 22 yo female with no family history of heart problems and I have generalized anxiety disorder. I am 5'9" and weight 145lbs and am very active on a regular basis but since these pains have developed I haven't worked out as dr request. I had a resting EKG and the cardiologist said I had non-specific t-waves. What does this mean? With all this rest the pain hasn't subsided but has not worsened either just remained there mainly when I am seated. The Dr who ordered the EKG suggested possibly costochondritis as the culprit. What could be the causes of these pains and is it possible to have heart failure at 22 when I've been healthy to this point?