I wish I was dead?

I wish I was dead.Im getting picked on at school like my bag being stolen and things out of my pencil case. My sister has a littel problem she is 25 but you do not want to get on the wrong side of her. My mum stickes up for her in anything against me when shes around and my father lives 300 miles away from me. I always ask my father if I can go and live with him but he just blancks me out. My mum went realy hard on it onetime and said it was because is partner did not want to start looking after me because they have no children living with them they are all at least 10 years older than me. My dad told me I need to learn to calm down and being with all the women hes bin with and all the children hes seen im the most ignarent child. He said I know it now I dont notice it but I don't know what to do I just feel like he dose not want me anymore. But I want him but I have no way of startin my life again everything I try to do or askif I can its NO I don't know what to do can you help please