Hi Freckly,
You seem to have said all the right things to your mum. She is lucky that you have been able to keep cool, not explode at her, and show her you still love her!
I haven't had your experiences, but I do know what it's like to have an unsupportive mother, who puts the man in her life first, and avoids anything that might 'rock the boat' even if it means denying the amount of pain her children are feeling. With both me and my brother there have been issues of abuse outside the family that my mother prefers to downplay.
This really is your mum's problem. You're absolutely right that you deserve more, and your mum is letting you down. I only hope that with time your mother comes to see that getting you to 'be quiet' is not going to make everything alright - her world is never going to be alright again.
I imagine she is also in denial about her guilt, and failure to notice and protect you. Admitting the full extent of your father's behaviour means having to think very deeply about herself - that is a v. painful thing to do and something that people avoid, even if ultimately it is inevitable and necessary.
Counselling not only helps with what happened, but what you can and can't do about the people around you. It sounds to me like you are managing to keep a sense that what happened to you was wrong, not your fault, and needs to be talked about, despite pressure from your mother - and that will be a source of strength for you in the future.
Maybe for the moment you have to allow your relationship with your mum not be good. Accept that, for the time being, you're not going to have the mum you want or deserve, and look for support elsewhere.
I used to go on and on at my mum, because I was angry that she was not the mother I should have been able to expect. I finally had to accept that she was not that mum, and to rebuild our relationship on a more honest footing, to let go of my expectations of a 'good mother'.
My dh also wants to 'shake' my mum. It's sweet, because I know it's because he thinks so much of me that he feels I deserve better! Having children brought up a lot of the issues again for me, but actually it also made me realise that I was right to have felt let down, and I hope that my dd can expect better of me.
Sorry to ramble on so long......!