Help: Marriage/Relationships and Trust

I am a 24 yr old adoptee, who has always had trouble with intimacy and relationships with depth. A little history...I was take from my mother when I was 2/3 and the courts gave her the opportunity to clean up her act. However her failure led to my adoption by my foster family when I was 7. My relationship with my adoptive parents has always had ups and downs. I believe I had un-diagnosed RAD, and often experienced extreme anger, distrust of others, lying and inability to accept affection from others. My parents rarely communicated the words "I love you," yet I know there was love there. I believe they were trying to let me cope on my own without pushing me to feel or demonstrate affection if I didn't want. Long, meaningful and lasting relationships were far and few between. When I was 18, in a need to get out of my parents house and in an effort to "find myself" I married someone I knew less than 6 months. It has had it ups and downs, and there have been a few instances of trust betrayal. Each time I think I have shut down emotionally. My coping mechanism pushes my husband further away. Well the pot has recently boiled over and we are discussing divorce. He wants me to decide if I want to love him, or can love him - and if I can't he wants a divorce. I had been considering divorce recently too. His reaction is understandable and now that I'm faced with the ultimatum I had been looking for, a deep fear has taken over. Even if I want to be on my own, I'm terrified of never finding anyone else. But if I stayed I'm not sure I can rebuild any form of meaningful intimacy that he desires. Has anyone experienced this shutting down when trust has been broken? Or does anyone have any thoughts? :confused: I don't want to be trapped by my adoption, but I know its effects are spilling into my life no matter how hard I try to control it.