Please help me! I can't take this life anymore!?

Im 14, and I lost my dad almost 2 years ago. I recently discovered that I have sadistic PD(wasn't diagnosed but show all symptoms and I just know know from myself ok) I hide my true personality and skef from my family and peers because I'm afraid they won't accept or like It. I cut myself every once and a while I promised my girlfriend I'd stop cutting and I did for almost a month then I had a breakdown( caused by stress and the fact that i almost really hurt someone(my teacher had thoughts of killing him) but my friend contorted me and stopped me before I did anything)and cut again. I would never try suicide, I'm against it. I do though seeing my disorder think often of hurting(or worse) the People causing my grief unfortunately I'm the one doing this most of the time so I would end up cutting again anyway. plz I need some advice, and none of this bullcrap consult a doctor or school counceller bullcrap. If anybody could help I'd appreciate it. Thank u.