I Feel So Unwanted.

I am almost 16 years old and for some reason as soon as I get close to someone, I push them away. Lately I feel like nobody wants to talk to me anymore. I have been self-harming for the past few years but its never really been anything too deep. When I told my "best friend" she didn't believe me and told me I needed to stop making things up. Since, we haven't really talked. I just feel like I am eventually going to lose everyone and I'm scared.