Hello -
It sounds as though you've caught an enterovirus, which is fairly common, especially this time of year. These usually will pass within less than a week, and in the meantime need to be treated symptomatically (treat the symptoms). In this case about the best you can do is stick to a bland diet (preferably the B.R.A.T. diet, Bananas, Rice, Applesauce and Toast) and take clear liquids as often as possible. If the
nausea gets to be too much there are one or two over-the-counter medications which can be helpful (Dramaine and Bonine come to mind); for
diarrhea there is always Lomotil or its generic. If the symptoms don't resolve within a week or if they get markedly worse, you should see a doctor, who may prescribe something stronger for the symptoms or test to make sure you don't have something more serious. By now, hopefully, the problem has resolved on its own.
Hope this helps. Best of luck to you.