@LudoBear
I have a brother, 22 months older than me, who I love to bits but sadly it's an awkward relationship which is my own fault.
Growing up I was a horrible child, constantly getting angry at my mum and brother if things didn't go my way. Turns out I have ADHD and I reacted the way I did as a child due to the ADHD. However my brother can't forget the way I treated him. Once he he was 18 he was about to get on a coach for 8 hours. We argued over something and I told him I hope the coach crashes and he dies. Horrific nasty evil thing to have said and I can never forgive myself for that. He even wanted my mum to get rid of me as a child.
Now we are in our 30s. He knows I will always be there for him and vice versa but he still sees me as the child who made his childhood hell. He never voices that opinion but I know its how he feels.
He lives 7 miles from me. I see him every Friday and Sunday to take his daughter to him & pick her up (neither him or his ex drive and buses are beyond rubbish here) but literally he comes to car to bring/get her bags and that's it really. But I know I can ring him and he'll come do DIY jobs for me etc.
God I didn't plan to write all that. Makes me sad and angry that we aren't close. I love him more than words can express and I'd be lost without him.
This is interesting, and I feel a parallel. Although it wasn't me who had the undiagnosed &/or unsupported issues growing up, there was a similarly ignored dynamic growing up in my family.
My younger brother may be on the spectrum mildly. He's very successful academically and professionally but when he was younger he struggled with all of the normal expectations outside of them home, and he struggled socially - although he seems ok now.
But the point I'm making here is that I place the responsibility for him being very aggressive and angry to me when we were children squarely on to our parents.
They should have protected me and they didn't. He was the favourite so they just wanted me to shut up and if he attacked me and I called for help, they came, but the anger they felt was directed at me. In their eyes, I was causing it and yeh I ended up with an abusive man
In an unhealthy family dynamic we are just never allowed to move past the character they project on to us. You'll always be ''ructions'' in your family's eyes.
My psychotherapist was helping me join up dots a while ago.
My family used me to feel better about themselves. I have a million examples of this and they were all frustrating arguments that wore me out at the time but I didn't see the crux of what was going on.
I did grow up feeling disbelieved, belittled, invalidated, unprotected ... and yet my family for all that they failed me in such a huge way, they still thoroughly enjoy projecting the image of me back on to me.
They had to ignore his bullying of me and make it my fault or they'd have failed to parent in a very basic way and they are not going there.
I have been lc for a year now, nearly, because they say such incredibly hurtful things and then defend their right to have said them and then tell me I have hurt them asking them not to be hurtful iyswim 
My role in the family is to be the stupid, unreasonable, awkward one. And even having stepped back for a year, the narrative is still that I'm sensitive, ridiculous, dramatic. They've learnt nothing. They certainly haven't learnt that they cannot keep hurting me.