Yorkiegirl - hope you're feeling better - this happened to me when dd was about 8 weeks old. I threw up constantly for a day - thank goodness MIL came to the rescue. I just fed dd in between sleeping and throwing up and it seemed to be fine.
Recommend - staying in bed as long as you can - rest will help your supply. Also fluids as much as you can manage once you can keep something down. Very diluted sweet things, like ribena worked well for me. And some plain cream crackers etc once you start to feel hungry.
If your supply does dip it'll soon recover as feeding gets back to normal.