What Are The Side Effects Of Taking Steroid Medicines?

I was given a steroid at the hospital 2 days ago through an IV i was then given a prescription which i cannot afford to fill. will i be ok if i was just given the one shot of the steroid and discontiued it after that? im kinda scared its going to give me a heart attack. ive been very tired and having muscle weakness and heavyness in my left arm now that the medicine is wearing off. im a 21 year old female.