I hope you got some food and some sleep. You seem like you can be that good parent to yourself that your own parents have failed to be. That's surely the way forward? Your mother and how she is won't change, probably. Can you accept that and be the parent she couldn't, or ? Or what?
Because in the end, do we spend our life as a child who wont accept that mummy and daddy didn't know how to look after us, or do we realise, hey, despite that I can do it for myself? I am putting it baldly to be clear, but I know on some level I have had to wrestle with that much longer than I wish. But we see it on the news, in drama and literature all the time, and in our friends and colleagues families too.
People are uneven, narcissistic and in denial of things. The package on offer from your mother is, agree you somehow imagined it and be dominated and controlled by her. That's all she has. You are right to rage at this. But unlike a child who has no choice but to rage and cry and be trapped when adults let us down, as adults we can, if we choose, make a different decision.
You can tell her you are unable to be in much contact while she keeps up this denial. You can follow up by not being in much, or any, contact. Then you have your own life to manage, and you can be the parent you needed for yourself, including taking action to get support for yourself.
If you think she should do it, why can't you do it? You have it in you, same as she does, if she chose. She is choosing not to step up. Are you making that same choice? Be kinder to yourself and look after that hurt child by finding better support for him than your family.