Adoption

I am so sorry, my case is similar to yours, only my grandchildren were forced adopted, also having a close bond with the eldest. My daughter had mental health issues, which turned out to be undiagnosed ADHD, then we suspected the eldest child to be Autistic. We asked for help, as at the time, my daughter wasn't coping with her own mental health issues, and her eldest daughter's meltdowns on top. Social services wouldn't believe us when we said we think she's Autistic and they blamed my daughter, which made her mental health worse. Several years later after her diagnosis, with therapy and medication, she's doing fine considering what's happened. They were fostered , then later Adopted. Fought for them, but how do you win when the social workers have made false statements and have the best lawyers? The children weren't harmed, and my family aren't violent or or into drugs. It's feels like I'm grieving for the loss of them when they're alive. You can register on adopted.com and hope you're reunited in the future. Stay strong.

I am grandmother to a much loved adopted little boy. He has a life story book which references his birth family, including his grandparents, so the starting point for any later searches is there.
He is enjoying a wonderful childhood with devoted parents, grandparents, aunts, uncles and cousins, full of good times and enriching experiences. I hope that this gives you some comfort.
We are all aware that our gain is someone's loss.