My Problems - Help Appreciated?

Hello. My name is Jade Marie Morgan and I'm 12 years old. Today I hope to tell you about my problems. But first you should know more about me. I'm a Libra, born on September 24th, 1997. I have shoulder-length brown, almost black hair. It is usually a frizz bomb when I get out of bed. My eyes are a mix of my mum and dads. They are pale, olive green flecked with black and yellow and a darker green ring around the iris. My skin has always been very fair and burns easily and extremely pale. My face is ordinary, yet occasionally people have called me pretty. I have a lot of tanned freckles across my cheeks and nose. Enough of me blabbering about myself, though. My problems. Yes. As you can imagine, my mum and dad met, true love at first side, they got together, got married, ect. My older brother Lee was born. After that ... things started falling apart. Mum and dad began argueing and my dad beat my mum until she was black and blue all over. Unaware to everyone, I was in mum's stomach, listening to the fighting. Mum was six months gone. When she found out I actually lived and breathed inside her, she confessed to my dad she had been seeing another man, Martyn, for a year. He hit her, of course, and instead of lying down on the floor and letting him, she hit back and scarpered. Martyn had recently bought a house, so mum moved in. I was born a week later than expected. I grew up forever ill, mum would dress me up nicely in lovely dresses and I would vomit and she would have to wheel me to the doctors. Dad never bothered to come and see me until I was about three. He hired a nanny while I was at his flat, so he could go out on the razzle. The nanny was a horrible witch and abused me and Lee. I hated nursery because the children made fun of me for being overweight. Primary wasn't much better. High school irritated the condition. People were calling me names like ugly and fat and smelly. I called back. I was cheeky to my mum and Martyn and they gave me good slaps. By then, my baby brother, Liam, came along, and RUINED EVERYTHING. He punched, kicked, slapped me, dragged me across the room by my hair and pulled chunks out, bit me, poked and prodded, and verbally attacked me. I tried to retaliate but my mum got me into trouble for bullying Liam. Mum and Martyn think he's an angel. And I commenced to self-hurt. I scratch the way down my arms until they're red raw and bite myself. I cry almost every night. I have thought about strangling myself to death with my school tie. Please help me, please.