How long does a stomach virus typically last? I'm going on 3 days of not eating, high fevers, nausea, vomiting, sweating and aching all over, help!

Usually 2-3 days. Most stomach bugs last 2-3 days, so you should either be feeling better very soon, or should be checked out. Especially if you are not keeping any fluids down, you are at risk for dehydration. Most gastroenteritis infections also have diarrhea, so if only the symptoms you describe, must also consider other infections, such as urine or lung, or something more than a bug.
Less than your symps. I suggest you see a dr. Soon. This sounds like more than a simple "stomach virus".