I broke out in hives because of food poisoning. At Kaiser, they ...

I broke out in hives because of food poisoning. At Kaiser, they gave me an injection of Prednisone. They gave me 10 mg. of Prednisone to take 4 10 mg. for 3 days, then, 3 10 mg. pills for 3 days. Since it was making me sick, the nurse instructed me to take only 2 10 mg. pills, and the following day, to take only 1 10 mg. pill. I took the last pill on Thursday. It's now Saturday, and I have the worst pain in my chest, my head and throat hurt. Can anyone tell me how long until this wears off? Is this normal?