I need help.

I'm thinking about ending it all tonight I feel so lonely and upset I don't know what's wrong with me. I just wanna leave this world everything feels horrible. I really need help but nobody will listen to me at all I help my big brother with his problems and I write him paragraphs about how much I love him and stuff he's 14 but he can't help me but I always try to help him. I feel like a tool to everybody I just want someone to understand why I am the way I am. I need help please.