over the years i have built up a list of foods that i can generally hold down pretty well. besides that, if i want it, i have it.
i stopped drinking soda nine years ago now, i only rarely have it as a mixer, but when i get sick, i down it. last weekend i had an awful stomach bug and couldn't hold down water for most of the day. last week i drank 4 2liter bottles of ginger ale and sprite. that's 3200 cals in soda alone. but you know what? it got water into my body [if water that needed a lot of filtering] and it gave my body some fuel to work with. and that is what i think the important thing is. getting your body something to work with. i have found that the sooner i get food back in me, the sooner i can get back to normal eating. but if i focus more on eating how i usually do, it takes me longer to get anywhere.
some of my staples are nuts, seeds, ramen [with added frozen veggies], saltines, saltines with butter, baked potatoes, baked potatoes with butter, bagels with cheese, orzo with teriyaki sauce [i go light on the teriyaki sauce, but the little bit tends to help clear out my sinuses], and if anything else appeals to me, i do my best to eat it. some of these things i don't really eat when i'm not sick [ramen, soda and saltines specifically]. but i keep them on hand for when i do. and i don't eat as well as i usually do when sick. but i find that by fueling first, it makes it easier to introduce the stuff i usually eat. last week i managed to add back in salads by tuesday or wednesday. i think the key is to not overload your stomach with a lot of things it really has to work at for a bit. give it some processed stuff [or light and easy things] so that you can add bit by bit some things to work at, as well as some things to help it back along [like yogurt].
so start making a list of things that tend to bother you the least and keeping those in the house. focus on eating those first and then it should be easier to transition to the food you usually eat.