You need to keep your chlorine somewhere between 2-4 ppm while you're dealing with the iron problem. Your question, "should I stay away from shock"? is a little misleading--shock is actually a verb, that means to raise your chlorine to a high level (which you should do, while you're dealing with the iron). It is not a particular product. There are packets labeled "shock", but they're just different forms of chlorine, usually with some other mystery goop in them that I don't recommend you add to the pool. I'm estimating your pool volume at about 5000 gallons (someone correct me if I'm wrong), and in that volume of water, each 1.5 cups of 6% bleach you add will raise your FC by 1 ppm, so you can use that as a guide to figure out how much you need to add at any one time. Until you have stabilizer in the water, you're probably going to have to add chlorine 2 or 3 times during the day to keep any in the pool, but if you don't, then you're gonna have algae to deal with on top of the metals.

Janet