If you want to change your ways then you must be willing to slam your own prison door. The punishment/sacrifice you make must should leave a waterboarding effect on your mind so you’ll think twice before taking this plunge again. The punishment/sacrifice you give yourself must exceed the pleasure you receive from the action you are trying to stop. Whether it be smoking, drugs, laziness (etc) if you’re not willing to let it hit home it will open the door again. You’re punishment must of course not be capital or leave some permanent scar but leave the mark to make you stop before you would even think about starting again.