My baby keep throwing up after every feed. Help??

So it started yesterday that my 1month old started to vomit after I tried to feed her. And her stomach sounds bubbly. And today she vomited Agian. Thinking its a stomach bug, didn't read the label right for the formula. How you have to refrigerate unused formula and feed within 24hrs and miss read that and didn't refrigerate it. So I think it's a stomach bug from that? What Can I use to keep her dehydrated she is only 1month.