For a few months now, I have had a 50 cent piece sized lump under my sternum that feels like it goes towards my back instead of sticking outward, as if it were one of my organs. It has a constant light, dull pain 24/7 and worsens if I drink alcohol , excerise, lift heavy objects, etc. I have also recently been having violent heartburn , which I have never had at all before. I also have light to medium heart pain spreaded throughout each day. For months now, it has also felt like I have mucus in my throat 24/7 which causes me to cough it up on a regular basis. I am male, just short of being 20 years old. PLEASE help figure out what is wrong with me, I feel like I am dying.