Hello, I have the feeling of a lump in my throat, my chest feels uncomfortable, I have headaches and I haven't been feeling like myself. I also coughed up a little piece of grayish phlem substance. I've had the lump feeling in my throat before about a month ago and it lasted for a week and went away, and I have been to an ENT and he said to get an esophagram done, but I never did. I'm just not sure what this could be?