I have a stomach virus and fever of over 101 along with my anorexia this has caused me to lose five pounds overnight. do i need to go to the er or will my regular doctor be okay as soon as i can make an appointment?

Gastroenteritis: Not sure what you have, because if it is entirely in your GI system and viral it is unusual to have a fever. Would need more info on other symptoms. Your weight loss is likely to be due to dehydration. If you cannot re-hydrate yourself fairly rapidly an ER visit might not be a bad idea. If you can keep fluids down, call and make an appt with your PCP. Hope you get better soon.