Hi, Gosh your story mirrors my own.
When I started my journey to find my birth family, I wrote to the address of my biological mother at the time of my birth.
To cut a long story short, I eventually got a phone call from a brother who filled me in about what he knew.
My mother was dead, but she had given birth to four children, three boys and me. She kept two, and gave two up for adoption.
I was eventually able to trace my adopted brother with the help of Birthlink. They found him through my mother's surname. I was able to have a lovely relationship with him for over ten years until he died last year.
My other brothers are also dead.
Like you, I have used Ancestry and together with a relative who does research, have also found out lots of information about my biological father's family too.
When they were researching for Long Lost Family some years ago, they approached me for my story as I was looking for my adopted brother at that time but they decided not to take it on.
I'm sorry that I'm not much help but please keep trying. I gave up for a while, but when I went back to it, everything suddenly fell into place.
Good luck 🤞