What Causes Choked Feeling In Throat And Bad Breath Constantly?

sometimes i have food get stuck in something on the left upper part of my throat. i have really bad breath all the time and I can feel this food in there that never seems to go away. i went to an ears, nose and throat specialist and she ran a tube with a light on it down my throat but said she saw nothing. i know it is there. sometimes when i eat hard bread it "catches" whatever is stuck there and i taste this horrible taste in my mouth. what is wrong with me?