Smoking....?

i started smoking a bout a year ago and my mom still dosent know. i turn 17 in less then a week. im not sure if i should let my mom know yet or not. it just calms me down when everything eles goes to ****. i hate having to walk to the other side of the block to have a cig or waiting for ger to go to bed. i dont know if i should keep it a secert for a whole nother year till im 18 or if i should just tell her. what do you think