It's complicated. I have a Golden Brother and a Golden Sister. I'm the scapegoat-cum-caretaker, and the other brother's the Sweet One. GB and I have both done some therapy - me more than him, but he stopped doing the 'witty' put-downs of his own accord. It's a good relationship, though no longer as close as we used to be.
As my therapy went on, we were all in early middle age. I gave up my caretaking duties and showed anger when the family jokes revolved around my perceived faults. This rattled everyone. I had a few long heart-to-hearts with my mother about my childhood: it was difficult. I felt better about telling her how it was for me, and some of the long-term effects. I don't blame her as such; what's the point?
My sister, however, has become very bitter towards me. I can only suppose she feels I'm betraying her by not putting myself out for her - I'll never know, as she now treats me like poison! She has a problematic marriage, for which she seems to blame me
and probably thinks I made Russia invade Ukraine as well as releasing the Covid virus. She's the most entitled of us, getting furious at thoughts of not inheriting more than the others from Mum. There isn't much to inherit, anyway; she's persuaded Mum to give her power of attorney, so I imagine she'll get her wish.
Families are odd, aren't they? You can't take away the childhoods we all shared, there is no-one else we know in the same way. But that same history can create deep emotional channels that simply wouldn't make sense in any other adult relationships.
Can you discuss any of this with your brother and mother, even superficially?