I know exactly what you are going through. Follow Sarita's advice. I had a phobia for years...still get scared that if I eat something that it will make me sick. I try to tell myself that I am not going to get sick and that if I do, oh well...it's hard, I know.
Start out slow...like crackers, jello, applesauce...work your way up to rice and steamed veggies and fruits...at least you will be comforted knowing that you shouldn't get nauseated with such bland foods and that if it did come back up, it wouldn't be too bad, KWIM?
I hope you get better soon!