That "plug me in" icon means that you MUST have the iPod separately powered in order to complete the restore operation. Requiring it to be plugged into power is a safeguard against a power loss during the restore, which would cause the restore to be corrupted. Borrow a wall plug from someone if you must, but that's what it's going to take to complete the restore. It could be that your entire problem was that the battery was very low, which caused the iPod's processor to get "confused." Charging it fully will fix that.