Hi dear..oh dont worry too much...You have a complusion to eat chalk from childhood are you...or is it since recently you started eating chalk...?????I am sure you know this is called pica. In my opinion, i would first like to deworm you.Take a single tablet of albendazole 400mg.. just one tablet, once only one day. Next thing, too much of chalk, is too much of calcium, which can cause depression and headaches and constipation? would you like to have these? So try chewing gum instead or anything else but that.do you feel depressed or aloof at times?? You may not be able to overcome your craving in a week... but you can certainly try to involve yourself in activities where you dont need chalk.... So dear keep off the cahlk or any thing related to chalk... do things out home.. run errands.. keep busy.. its just a mind game.... its the mind which is telling you to keep off... and you will keep off for it this week. I hope you will pay heed to my advise dear.. get back to me if , if it doesnt work... Take care