I need help I’m freaking out

My baby has been throwing up for a week. On Sunday he was throwing up more frequently and having diarrhea. He has a post nasal drip cough and runny nose. I went to er because he was getting dehydrated and only recommendation was giving him pedilyte and if that doesn’t work they would admit him. Well flash forward 36 hours all he can drink is pedialyte and things are not getting better when I give him his actual formula. I noticed his hands are ice cold, they occasional turn purple (showed docs they weren’t concern) and his temp is slowly rising (not a fever yet).