What Causes Throat, Teeth, And Chest Pain?

Hello, I have been having throat, teeth, and chest pain for the past weak. The pain tends to get worse after drinking water or lying down, and I have mucus in the back of my throat. Today I even notice that I have black strands at the back of my throat. Other symptoms that I have are poor food digestion, anal fissures, and intestinal pain. I have been to the doctor many times, but they haven't got a clue what is wrong with me. Any suggestions? Thanks.