I Keep Eating Rocks,cement Gravel,dry Wall And Chalk...my Mums Threatened

i keep eating rocks,cement gravel,dry wall and chalk...my mums threatened me to stop,how? every time i cry and tell myself ill never do it again it only lasts a week, how can i stop! ppppppllllleeeeaaassseee help me, cure me, i will do anything,i am desperate, i don't want it to effect my health