Try this article on Panic Attacks.
Its in the Huffingtonpost about the psychology of trying to help someone to stop smoking.
Emetophobia is the fear of being sick. The anxiety that comes with the thought that throwing up would be the worst thing that could happen and must be avoided at all costs. It blights many lives because every activity has to be planned, every meal is thought through and calculated. The mind is consumed with avoiding the disaster of throwing up, even if the event hasn’t happened since childhood!
Other fears such as flying phobia, agoraphobia and eating disorders can often have the fear of being sick at their root. Throwing up seems like the ultimate humiliation and embarrassment, something to be avoided at all costs. Sadly the costs are restricting your life to a miserable degree.
So what’s to do?
Try this Huffington Post article on the subject.
Or this webpage on my site about the fear