Try eating plain crackers or ginger biscuits, gingerbread, ginger cake or ginger ale, or just about anything with ginger in it.
Have lots of small meals, don't try to eat a "full" meal.
Take frequent small sips of plain water, or with a small amount of juice/squash/cordial added, or with a squeeze of lemon (doesn't matter if water is chilled or warm - which ever you like best).
Also see if you can lay your hands on some preggie pops - the thought of the flavours makesme wanna puke anyway but loads of people buy them so they might be worth a try.
If you do feel the need to puke, the best thing is to relax as much as possible and not try to fight it, go with it, I know that sounds awful but it really is best, then when it is done, rinse out your mouth or brush your teeth (to feel more comfortable) and take lots of small sips of water, or maybe try an isotonic sport drink as this will help repace los body salts as well.