Diarrhea since yesterday and today, been vomiting all morning yesterday but haven't eaten anything yesterday nor today could i be dehydrated?

Gastroenteritis.: This sounds like gastroenteritis, which can last a few days. But whatever it is, you could certainly become dehydrated if you're losing fluids via diarrhea and vomiting and you're not able to replace your losses. Try to take in sips of fluids, like water and electrolyte replacement drinks, even just a little at a time. That will help until this ends. See doc if this doesn't end in a few days.