When you have a craving you should do all that you can to help to calm yourself down to reduce the need to slef harm.
Many people find it helpful to have a nice hot bubble bath to help to calm themselves down and to reduce the need for self harm. To do this all you need to do is run yourself a nice hot bubblebath and maybe light a few candles. Lie in the bath and let your troubles wash away.
This works by adding heat to your muscles, relaxing them and reducing the physical tension within your body. Once the pysical tension has gone, your mental tension begins to release and you will start to feel alot better.