Help!!! i don't know what to do?

about 5 years ago my grandfather died it didnt really bother me that much then the next year my parents got in this huge fight with my aunt and uncle so then i never saw them or my 3 cousins again then the very next year my cousin joined the army. my cousin is my best friend in the entire world he was there for me when no eles was and its been so hard on me i cant stop crying almost every day sometime i blame myself for my misfortune i blame my self for my grandfather dieing and my parents fighting and my cousin leaving i have been so depressed for about 3 years now and its just not getting better. please someone help me before i go out of my mind!