Suggest Treatment For Fever And Swollen Tonsils

My daughter is 16 months. Tuesday she started fever and vomited most of the day. We visited the dr and he said red throat and swollen tonsils. The vomiting and fever stopped by the next morning when she had 4full diapers that didn t look like diarrhea. Today she woke up and after breast-feeding she vomited again. It lasted all morning and we went to ER being concerned with dehydration. After 6 hrs in the ER they prescribed antibiotic for possible bladder infection. The urine from the bag showed no infection with the stick but the one from the bag was inconclusive. The dr said she might have, better put her on antibiotic. They could not have a caters on the child. During our stay in ER she was given Zofran that stopped her vomit and help her drink. They gave her 1/2 pill with one to take home. She had 3 full diapers with diarrhea, very foul smell. I forgot to mentioned that we had supper last night at a restaurant and I felt very sick once back home. Felt like vomiting but I didn t. No foul stools or diarrhea. She is very tired, breast feeds now, played a little but no energy . Out of help with here. Thank you.