Hi I'm close to your age almost 16. And I get you I really do, I tend to feel this way too. So its not just you. Hmm I think it could do with the fact that we're teenagers and have weird emotions. For me I always feel isolated. I have 6 siblings but I never feel accepted in my family (not to mention that my adoptive mother wouldn't mind me dead) but like you I wonder what I'm doing alive… When I was younger I had a close chance with death and God kept me alive for some darn reason I don't know if I'll ever know the answer too since I feel like I make everything worse for my mom and family by my very existence. I wonder I really wonder sometimes... Are you bipolar? Also have you thought of taking therapy? If you want to talk more I'll be here.