Would Anyone Even Care If I Was Gone?

I am 14 years old, I have moved from Los Angeles to Greece to Las Vegas. I was a normal girl. Then when i went to Las Vegas, something changed, i was happy, like so happy. It was so different, i mean i had been happy before but not like that, the people the place everything just came together to make paradise. Except for my mom and sister, they were a nightmare, but because i was around people that loved me, i didnt mind. Then one 2 months later my dad called and said my grandma died and to come to Holland to visit for two weeks. So we did and he has still not let us leave. It's been 5 months. Everyday is a nightmare, i cut my wrists, i starve myself and i make myself throw up, i take pills, i lie alone in my room crying because i am so miserable, it's like my heart shattered into a million pieces, i hate my family so much whenever i speak to them for even 5 minutes i fall to the floor screaming and i have a mental breakdown. In school people are making fun of me, by how i dress and how i am. If things arent bad enough, in my spare time I daydream of killing myself, but not just like a gun to the head pow I'm gone, I mean like a whole process like every detail from the entire day up until that moment, sometimes even after I'm dead, how people react, what happens, in so much detail it's like I'm living it, every time it's a different scenario, sometimes falling off a building, sometimes cancer, sometimes bleeding. It's become so normal now that I want to actually do it. The only thing keeping me alive is the thought that I might go back to Las Vegas again and be happy. But i don't know how much time I can handle this, and every one i tell thinks I am being dramatic and that how i feel is stupid. So I wonder, If i dies, would they start caring?