I Am Having Side Effects From A Medication I Was

I am having side effects from a medication I was prescribed. I was prescribed Prednisone 5 days ago, and was told to take 3 pills 3 times a day for 3 days, and then 2 times a day for 3 days, however I started getting dizzy, lightheaded, jittery, and had trouble sleeping. I stopped taking it yesterday, but I am still feeling jittery, dizzy, and shaking. Should I go to the emergency room immediately or contact my PCP next day?