I must say that I know exactly how you feel. I get the feeling as if I am putting a finger down my throat as if triggering my gag reflex.  It always triggered when I get nervous or excited about something, mostly when Im know that im going to be in social situations.  And once I think about it there is no getting it out of my mind. It have controlled many aspects of my life and has ruinded my life. I cannot eat in restaurants at all unless i get a carry out order,  I dropped out of college cause of this.  The last few years though I have found that  Paxil has helped me. But with no health insurance it is very difficult to live with this anxiety.