*Sigh* Can I just kill my self already?

I met a boyfriend online through a chat room, I know thats stupid but its not that. I was with him for 1 year and a half and then he left me for a girl he met at his school. I was so depressed. I told him everything, no secrets. My number, my email, facebook, I sent him pictures, and we said I love you over 100 times. Im 13 so im very young and hes 11 even younger. I self injure and I am addicted to it. I needed help so I told him and he laughed (While we were together). Now his girlfriend texted me and acted like a sweet innocent happy person, i called her spoiled, she flipped out and sent me an irritaiting text message. It made me want to die. She knew every secret. She used it against me. I cried and cut even more. Now I feel like commiting suicide, whats the best way to do it. I want it to be fast. Thank you, Sabrina Marie Akers