What Causes Sore And Swollen Area Under Breast?

Feels like I have indigestion under my left Breast . I have taken gas x to see if that would help. It has been about two weeks now , it hurts to lay on my back or side. It feels so sore and it is swollen . If I stand up I can feel like indigestion moving In that area. When I lay down I feel a burning feeling in that area. It hurts to bend over or lift myself up out of bed