ok, need some med student help.

We went to a restaurant like a week ago with my mother.
After a couple days, We got severely ill.
I felt fever but overall was ok after a single day.

But my mother has been sick since.
We went to the doctor, but he only gave her:
acetaminophen and cephalexin.

My mother has fever, headaches, shaking chills, overal dicomfort and doesn't want to eat nothing.

I would love if you guys could recommend me something to lessen her symptons.