I eat stuff like ice, baby powder, finger n toe nails, thread frm clothing etc. i tried to stop but can't. what's the problem n how can i stop this?

Get checked out: You are describing symptoms called pica. This can be several different conditions. That is why you need to be seen by a physician to be evaluated and get blood work done to help determine why you are having an appetite for non nutritional things. You probably need to be seen fairly quickly if this has been going on for more than a couple of weeks.