I’m sorry to hear that your brother is having such issues, but I think your decision was the correct one. You obviously didn’t approach it lightly, and as you explained here, connecting again for an event he’s vehemently against would only ruin your special moment and would do nothing for his relationship with you (or his happiness).
I had to cut off contact with my only sibling after years of trying to make things work. She’s a narcissist, a pathological liar, has a god complex, and a host of other problems no one else will confront while allowing her to inflict pain on others. I hate that I essentially don’t have a sister anymore, but the damage she’d done to my family just couldn’t be allowed to continue.
Sometimes the hard choices have to be made.