If you are able to take some time to rest, sit upright with your head propped on something. If you can do it outside in the fresh air even better.
Just remember to keep your breathing even and maybe try sipping some pineapple juice very slowly.
If you don’t like that try sipping liquid jello. It is basically jello you prepare with 1 part boiling water, 1 part warm water, and which hasn’t “set.” This is also a good stomach flu remedy, by the way.