Meditation is often recommended as a strategy for dealing with painfull and distressing thoughts. It doesn’t help everyone all the time and may intensity certain thoughts.
Guided imagery offers a useful alternative. The visual approach to relaxation helps you create a mental happy place by creating pleasant scenes in your mind. Adding vivid specific sensory details to your mental image can help you release stress. Take your mind off the urge to self harm and promote feelings of peace and calm.
Search guided visualisations on internet and look at apps that play calming music to go along with your guided visualisation or actually use the spoke word to guide you through. There are free apps for this. You can also buy ready done guided visualisations in cd form from amazon.