How do I get help with/from psychological abuse?

I am 17 years old, 18 late February, and I no longer feel safe in my home. I live with my legal guardians, ages 62 & 70, and my biological brother, 12. Our relationships have always been tense at best, and when things get heated it always ends brutally. I was taken in by my guardians, who were family friends, after the deaths of my parents when I was about 5. My brother was taken in by them - as a baby - 6 months before my father's ping, so when I came to live with them he was already largely integrated into their family. I was ually abused by another family shortly before coming to live with them, and have been diagnosed with ADD/ADHD, Reactive Attachment Disorder, and high-functioning Aspberger's Syndrome (sp?), so forming proper relationships is very difficult for me. My childhood and preteen years were tumultuous, largely because I was struggling to deal with these issues and learning to cope with the strict and hurtful verbal punishments from my mother. She would slap me for things, which truly is not that abnormal. Apparently I have always had a bad relationship with my brother, even as children. Late my 8th grade year, I requested help for suicidal feelings and depression. I had seen therapists off and on. Once I hit high school, things went terribly downhill. I met a boy, thought I was in love, and had with him. He was a senior, 17, and I was 15 and in 9th grade. My parents always disliked our relationship, even while ignorant about the , but me and the boy thought we were going to be together forever, and at boarding school, it seemed so easy. My parents found out, pulled me from the school, and sent me to the local Catholic school. I still talked to my boyfriend, and seeing as he lived in the same area, we tried to see each other often. My parents threatened with a PFA. The boy went to another boarding school for a post-grad year, and became heavily involved with drugs. I looked to his best friend for solace, and started a relationship with that adult instead. I only say adult because he was 20 at the time. Things got worse, they fought over me, and when the original bf came back, he still used marijuana, and I got tied up in it as well, because while we no longer had anything in common, I wanted him to be the one, and it also eased the stress from my homelife. In the spring of my junior year, the issues at home reached their highpoint. My parents found my weed, and my mother and I got physical. I was sent to the hospital's psych ward, where they therapists there told my parents to try and press charges. Things were worse when I came home a week later; my mother now openly mocked my cutting and suicidal poetry and drawings. She would tell me I would never do it, that I was too scared. She reminded me how I was "no-good" and would never amount to anything. I started smoking again, but was not caught this time. However, my parents called the police and turned over my weed from the previous incident. I am now on probation for possession. I dropped the old boys I was interested in and tried to find more promising beaus. I ended up with an ex-con who had broken his father's jaw and aulted a cop, among other things. A few weeks into our dating, he left me for my friend, and I learned I was pregnant from him. This was in April; I was still in school. My mother knew, and was surprisingly civil about it. The baby died at 10 weeks in July, and I need a dnc to remove the corpse. (Had I carried to term, I would be due in a few weeks). Things died down and I tried to get my life back on track in the fall. However, my brother began getting abusive. Not hitting me, he tells me I am a "mf-ing c***sucker", and that I deserved to lose my baby. He hurts himself and blames me so that I get into fights with my mom, who tells him to hurt me physically, like I did him when I was a child. He is a large kid, plays both hockey and football, and really could hurt me. My mother tells me I am "no-good" for fighting with him, and that I will never go anywhere in life. My father just stays out of everything. I am afraid to go to my mother to schedule doctor's appts. After I lost the baby I had a bacterial infection that I was given antibiotics for. My mother saw was I was taking and told me I had trich and was a , and that all I want is to have . She refuses to make the appt. for me to get tested for STDs, because me wanting to get tested apparently means I'm going to have with someone, not that I'm concerned about my own health. I finally told her about my bladder infection, but only after it got unbearable and the nurses at school threatened to call her. I was so scared of the things she would say about it. I have a wonderful boyfriend now, someone who is so good to me, never does anything against me. She says I'm using him. If I act like I love him, I'm too young to get involved with someone and I'm just going to get pregnant again. I keep decent grades, a 3.3, but it isn't good enough. I receive