My son is 2 poss autistic and had tonsils removed last friday now high fevers and thrashing himself screaming ent said give more time but i'm worried?

Call your pedi: If your son is continuing to have fevers, best to also contact his pediatrician. Perhaps his pediatrician can check him- look for other signs of infection and confer with the ENT doc.

Needs more fluids.: Thrashing about,is most likely from pain,and cause of fever is likely from dehydration,encourage more fluids,if this does not help,call your ENT surgeon,or E.R visit for hydration