This is a question, I am not judging anyones beliefs or ways of coping. I just want to know.
Is throwing up or seeing someone else throw up the worst thing you could imagine that could happen to you, personally? I don't want you to all to try and think of something worse, but try to go with your automatic response to the question.
Is your daily plan to avoid getting/seeing sick? Is avoiding whatever your phobic of, more important to you than facing it?
Right this second, if you knew that facing your greatest fear, have it happen to you, with this phobia still racing round your head, meant that you would no longer have to fear it, would you let it happen to you, if you had the choice?