"your situation is honestly uncanny my brother is the same - golden child and unable to be criticised and totally enabled by our mother"
@Honeynutcheerios I'm another one in almost identical situation.
Same as you, I felt we were both to blame. Have tried reaching out at various points and got nowhere.
At one point he made me jump through a load of hoops (via text), admitting it was all my fault, admitting how awful I am etc etc. i gritted my teeth and agreed to it all, paid lip service.....when he then started demanding that I flagellate myself to his wife (who was a pretty big part of all the issues) I just couldn't do it and communications broke down.
Since then I have tried again to extend an olive branch but have been blocked on all platforms.
He has moved house so I no longer know where he lives (and would be unlikely to just turn up anyway) so that's that. Door firmly closed.
It's been about 7 years now.
When it happened, my dad was pretty furious with his behaviour. My mum just kept excusing it / brushing it under the carpet while telling me to just bend and do as I was told because "you're usually so good, you usually do as you're told" 
We both have kids now. Parents actively involved with my kids and his kids. Which I am relieved about because it would be a lot worse if the fight between me and him had come between him and my parents (which it almost did), but our family has been ripped apart. It is like a bereavement.
They only mention him and his family to ge occasionally, if it's relevant, and I just respond politely, like it's an acquaintance.
Fairly sure they never mention me to him because people always kind of walk on eggshells around him because he is easily offended.
If he (or his kids) phone my mum when I am at their house or they are at my house, my mum will take the phone into another room and close the door and have big long, secret chats.
If I phone my mum when she is with them, she doesn't answer 
Things like that I find unnecessary and frustrating.
But largely I just feel heartbroken and like a part of my childhood is gone. I'd give anything to make up and find it hard to accept that is never going to happen.