I'm sorry @Ed1975, it must be such a difficult thing to learn about your brother. It's okay to not know how you feel about it. You obviously care for your brother and just wanted the best for him, so what you found must be quite upsetting.
I know it's not the same, but i found my original birth records 4 years ago to track down my biological family. I found out that I had an older sister who was also adopted out. Apparently she dies at 18 months old. I didn't even know she existed before learning this, but it hit me quite hard. I felt like I missed her and it felt like a fresh pain and loss to me, even though it happened about 55 years ago. Its hard when you can't even really understand what all these feelings are when you find out something shocking like this, even if it was a long time ago. Like your brother, it may have been a long time ago, but finding out the truth is new and so it's very confusing trying to make sense of it all. Maybe you wrote it here as just a way to try to find some sense in it all.
You looked for him for all those years and finally found him. Yes, with some very difficult and emotional truths, but you cared enough to keep looking until you found him. I feel like that honours his existence in a way that others failed to do. And I think that's important and matters a lot. You've given him something that he's deserved for so long.