Sometimes When I'm Eating Food Doesn't Seem To Want To

Sometimes when I'm eating food doesn't seem to want to go down and it feels as though it is stuck. I feel like I need to vomit to get it out and when I force myself to do so, it is full of mucous. It happened once when I was eating smoked turkey, scared the life out of me and it was uncomfortable, must have went on for a full fifteen minutes! Another time it happened but I was eating fried chicken and the same thing. It feels as if a bubble is forming and the food gets trapped and I have this uncomfortable feeling that I have to force myself to vomit. What is causing this?