What is wrong with my dog?

Today is Wednesday, and this past Saturday night, I got Taco Bell around 10pm. I usually give my 1 year old shih-tzu little pieces of whatever I m eating. Well I gave her a few pieces of my chicken quesadillas, and the next morning, we were both so sick! I was in and out of bathroom all day Sunday and Monday, and she was puking and pooping everywhere! Well, it wasn t until around yesterday evening that my appetite slowly went back to normal and I wasn t rushing to the bathroom every time I ate something, but she is still puking and not eating. She was at her worst on Monday, as was I. She was very tired and was not active at all. Yesterday, she acted normal, running around and began drinking again. But then she threw up everything she had eaten last night. Today she s acting normal but still not eating. Her stool literally looks like chocolate pudding.
Is it just a bug? I m pretty sure we had the same thing, so is it just taking longer to get out of her system or...? What should I do?