Searched and shot down

Hi, I’ll try to be brief, my adoption story - I’ve always known, so it never phased me, it always felt like a good story really. My mother and brother were also adopted. In the past couple of years I’ve helped them locate bio families, and honestly it’s gone as well as you could hope for. After this they encouraged me to look. I’ll admit I never felt the need as a teen/young adult, but when I had my own child I found myself wanting to know my heritage - and to be able to explain it to them. So, I searched, along with my friend. Within a short while we had located my bio mum to America (she was originally from Ireland). Without boring you with a million details; I sent a few letters, and even photos - as that’s what made it real for me. After never having a soul who looked like me I’m confronted with the undeniable fact that these people are biologically mine. Anyway fast forward her ignoring me for months, I finally got a reply from a made up email saying she wanted me to know she’s not my bio mum (she is), and to stop searching - why should I if she’s not who she is!? To clarify, I truly just want to know my ancestry. Would it be nice to have to loose friendly contact that I’ve witnessed with my brother and mum - of course, but I’m ok without it. My family are amazing, I’m very lucky. But since opening Pandora’s box I’m struggling with the refusal to acknowledge I was born. I don’t see why I have to pretend I don’t exist. So... that was my short version! Thanks for listening : ) I thought talking to people who understand would help.