How Can Stomach Infection Be Treated?

Yes please, Monday in the evening I came down with a stomach bug my Grandson had the week before (we have raised him since an infant). He had the traditional vomiting/diarrhea lasted 2 days and he s fine. Mine started late night Monday the16th. Wracking chills/fever and diarrhea. It continues ..... tried eating 2 tablespoons rice. today I ate a small banana and have been trying to stay hydrated with gatorade, pedialyte and water. I had a fever but low grade and not today. Wednesday it was green, yuck! Thursday it was black with some regular colored blood and abdominal cramps started in. Today it is back to the blood thing and I am very weak (not my usual perky self). I know sooner go and within a few minutes I have to go again but there is nothing left in me. I have lost 7 pounds since Tuesday (not complaining there)! Have any ideas how I can get this under control? Thank you for your help. Polly Heaton