Long Story Please :'( Need Familyy Advicee ! ASAP

Well whenn I was 3 my mum and dad had a row,, my dad ended up in a coma and still suffers an illness todayy anywayss I stayed with my mum and 3 brothers at the time I didnt mind I got to 6 and things wernt good everynight something would happen my twin brother would get hurt by our older brother(19) at the time they were 13 they used to push me and my twin brother down the stairs use to hit us and force feed us , my mum thought it was play fighting and she was useally to busy finding other men she soon had gone through 4 men (mark,paul,tim,steve) I found this so harrd as my mum kicked mark out through drinking and tim didnt have enough money and steve f5674 knows paul soon got so involed that we had a baby sister by 11 I moved out and went to live with my dad and my twin brother we now live in a house thats been extended as my nan and grandad allso live in it well when I was 12 13 I was inbetween to houses stayed at my mums some nights and dads others now I only see my mum on sundays but recently me and my mum had a row as she saw me smoking and now I never see her as she thretend me wiht my life and im so so so scared and my dads bakc in hospital iin a coma as hes got a bleed in the brain and I duno where to go who to talk to and my mums just saying I must stay away from her crnt see her or my sister or brother and I want to be part of there lives I dont know what to do help !!! sorry long storry if any one is boverd thanks