Self harm behaviour is an immature defence mechanism to deal stressful situations. It may sometimes happen when one is not able to express what is going inside your brain.
It may also happen when we care not able to control our desires and when we are denied of it our thinking reacts in an aggressive way.
Next Steps
so it's advisable share your thoughts and emotions with closed ones when you are in stress, anger or frustration so that you do not harm yourself.
Health Tips
get some professional help. go for counselling.