AM i doing the right thing..am i the one in the wrong?

Here is the deal. I am a 28 yr old female who can't move on from my past. First let me start off by saying i am adopted since i was two years old. Most people would think that the adoptive parents would be the best in the world. WRONG!!!! My adoptive parents was horrible to me as a child & early into my adolescence. My adoptive father, ually abused me & my adoptive mother was verbally, emotionally & physically abusive towards me. She acted like she hated me. My adoptive mother 2nd husband even ually abused me, not physically, but he hid a videocamera in my bathroom. My mom found this out & blamed me. And even begged her husband to stay with her. My whole life i wondered why in the world did she adopt a girl. Besides me i have an older brother who is also adoptive, who was treated bad by my mother only. THen i have a younger brother who is the biological child, who got everything he wanted in life plus. I always had to work for everything, nothing was every handed to me. I was treated so bad that my self esteem is shot to pieces, to were i can't develope close relationship with people. So now i am fed up. I am tired of dealing with it. I don't want to be portrayed as the adoptive child with problems. Not too many people know my story, only my older brother. I stay to myself. Well as i got older I quit dealing with my adoptive family as much. I don't call them or see them. The only reason why i talked to them as i got older, b/c i wanted a family. Anyway my older brother tells me i am being silly, that i should have a realtionship with them. It hurts me that he thinks this way. He even know about the ual abuse. I never told my family about what my dad did to me, but they all know about the video tape. It makes me mad even at them, b/c i was 13 or 14 when it happened & know one did anything. I know this is too much TMI, but what should i do?