Hi there. I went through your query in detail and can understand what you must be going through. Emotional problems at your age is not common. Depression is just one of the problems that you are going through. You have much larger issues at hand and that is of underlying developing personality disorder. It is quite possible that your attempts at self harm are due to that. It is important that you talk to your parents and seek a psychiatric consultation to undergo complete evaluation without any delay. Treatment with medications and psychotherapy can offer you much better chance of feeling normal again.
Next Steps
Visit a psychiatrist and get yourself evaluated.
Health Tips
Maintain a diary and start venting out your feelings on a daily basis.