Fear of vomit

I'm (22F) and I have had an irrational fear of throwing up ever since I was a child. This means I can't watch/hear somebody throw up and when it happens, it causes severe anxiety and often leaves me feeling low because I tend to keep playing the scene in my head long after it's done. A couple of months ago, after an episode of gagging, my anxiety levels went sky high, upto to the point that I was dreading getting out of bed. It got so bad that I would throw up because I was so anxious. I also have stomach issues(gastritis) which makes me feel nauseous and this only adds to the problem. All the anxiety made me lose my appetite and I was unable to eat. This made me lose a lot of weight and I'm already underweight as it is. How can I overcome this?