Cutting is the only thing that makes it better

I'm a 16 year old girl and i pretty much hate life. I used to be really happy until about a year ago. I'm not sure what the trigger was but I gradually grew to have intimacy issues like i cant stand being in close proximity to people, I dont like people touching me and I'm incapable of showing much affection, not because i dont want to but because I cant, I dont feel anything like love for anyone, i like my parents, they're great but I dont love them and I dont love my friends. I thought i might have been over exaggerating but my grandmother who i saw every week died a few weeks back and i felt nothing. But the problem is that people think that gives them a free pass to say and do whatever they want to me and it hurts. My friends openly call me heartless and a freak, saying they dont like to be alone with me because I'm depressing. I spent along time not caring but being this alone is taking it's toll. After i spent my 16th birthday being ignored by my friends i came home and i cut myself and it made it all go away, i felt like all my worries had gone and i was normal, i do it every couple of days and it helps me get through. But recently i feel like it's not enough, i just dont really see the point of living when you isolate yourself from everyone around you. I've tried just riding out my sadness an not cutting but i when i do i feel like I'm going to be sick and i get headaches and they only go away once I've self harmed. I dont want to be a freak but i cant change the fact that i dont think and feel like other people.