I've had a lot of problems with this. I use to have major problems with throwing up due to anxiety and it wouldn't stop until my fear of the situation went (usually meaning till it was over). I've gotten better at controling this by trying to make myself excited about the event. Try focusing on the positive rather than negative. That probably is the best advice I can give. I know it is a lot easier said than done, but the more I"ve practiced it the better I've gotten at it.

((((((((((((hugs)))))))))))