A " failed " adoption. ( I am the adoptee ).

I'm new to this site, didn't think there was a forum for adoptees until I came across your story.I was adopted when I was 5-6yrs old and only stayed with my adoptive parents til I was 10-11years old. My adopted parents gave me away to the people who helped them adopt me (private adoption) I didn't think they were allowed to do that and it was legal.After 25 yrs later I still try to understand why they did it; I still have their legal name so am I still a part of their family?? Are there any rights for adoptees ??