Sciatica, The pain feels like a knife

On Monday morning I fell down the stairs and my lower right side of my back slammed on the stairs and knocked the wind out of me. I went to the ER when I realized I could stand straight up without being in a lot of pain. When I went their, they gave me pain meds and sent me on my way. Said I have sciatica and didn't take X-rays. The pain is bad, and I couldn't sit without being in pain, couldn't stand straight up and it hurt very bad to lay, move, anything. When I am laying or sitting, it's very painful to scoot to the left or right, and couldn't lay on either side. Today I am getting around better but when have to get p from sitting, or move my right leg out of the car, I have a horrible shooting pain in lower right back area. Takes my breath away and hurts sooooo bad. I also can feel pain in that area when I take a deep breath. I work out everyday until this happened. The pain is bad enough still almost a week later that I want to take something. How long til it gets better and when should I workout again. The pain feels like a knife, and hurts when bending over, having to get up from sitting, laying on either side, or if I am standing and pick something up, or if I leave lower body in one spot and then pivet my upper body to turn a light off or anything of the sort. Please help.