What Causes Chronic Discomfort In The Upper Chest?

I have a pressure feeling in my upper chest area, I am not sure what could be causing it. I did have a really bad episode of heart burn awhile back in January and then I had continuous chest pain that went to my back during the week I had the episode of heart burn. It subsided, but now I have a pressure feeling in my upper chest area and when I lay down the pressure feeling gets worse. I also live in a town house that potentially could have black mold, which could be causing the pressure feeling in my chest. I would like to know what could be causing my pressure feeling, as it is concerning me.