Ok, I am reading this book right now called "Hope and Help For Your Nerves" by Claire Weekes and here is a little blurb from page 55 that I thought might be of some help!
Fear of Vomiting
Many nervously ill people are haunted by fear of vomiting in public, but I have not yet met one who has actually done this. Many have gagged gently to themselves or have hurriedly left the hall to gag in the lane outside, but vomit food--no. This is remarkable when we realize that short of putting his finger down his throat, a nervous person could hardly stimulate his stomach, abdominal, and throat muscles more than he does by his tense, anxious control of them. It is not as easy for a healthy stomach to vomit food as one imagines.
If the nervously ill person were to let go and give up the struggle to try not to vomit, his muscles would gradually relax and vomiting would even be LESS likely. If he does not vomit while tensely on guardm he certainly will not do so when he relaxes and lowers that guard, and how much more cmofortable he will be.
WOW!! I am glad I bought this book! LOL