Low iron

Ok I 've had it ! I am going to my PCP tomorrow. I've been on the iron pills now and I am feeling worse. I had to go home early from work yesterday. I am so tired of feeling so yucky. I am wondering if my iron level hit too low for the pills to work? I constantly deal with headaches, leg cramps, muscle aches, chewing ice all the time, craving carbs, tired, cold..... ugh! I am never sick so this is really frustrating me.