Advice?

Well, I know most of the people on here have been pregnant before or something and the problem is that, well, do they get an abortion? But I’m a little different.
I was adopted when I was a little over a month old. My mother had a brain tumor and was partially paralyzed. My father was on meds for neurological problems (I don’t really know what was wrong.) So, after my mother had me, when she took me to the doctor, my dad came one time. He asked the doctor if there was anything to give me to keep me from crying. The doctor, of course, said “Babies cry. Why would you ever want to make her stop crying?” and my father replied, “Well, I love her but sometimes the crying is just so annoying I want to hit the wall!”
Needless to say, the doctor called DSS. They told my mother either put me up for adoption or leave her husband. She put me up for adoption and a couple who were also friends of the family took me in because the woman was barren. These people are my parents now, and I’ve lived with them my whole life.
Well, over time the story of my biological family has started to unravel between me and my adopted mother. As I get older, she tells me things about them. One time she said it was a miracle I was even alive. Of course, I asked, “Why?”
My biological parents got pregnant two years before they had me. My mother had an abortion. I would have a sibling if not for that. They almost had me aborted, too. My parents say that they loved me, but what parents love their kid when they almost killed them? I don’t know what to think about it. I don’t know whether to hate them or love them or what. I want to meet them someday, but what if they don’t want me after all the trouble I’ve caused? Should I be angry that they murdered my older sibling? I don’t even know if it was a boy or a girl.