You are certainly in the right place to heal from this and I really hope talking to the men here helps you.
I absolutely understand your desire not to be consumed with anger, however when I here myself that an adult could do such a thing to a child, and the distortions and terrible after effects it has throughout someone's life, it makes me! feel angry, because it is! wrong.
Imagine for yourself that you heard that a child under 10 had had sex with their parent. if it makes it easier, imagine that it was a girl and her father sinse at least as far as the wrong goes, it's very much the same.
I'm not suggesting you should!hate your mother for doing this, indeed as far as emotions go I don't think the word "should" can ever be used, as it's very much your own business to work through. However, I do wonder if you do feel some reluctance to accept this as a serious hurt, in order to unravel all the consequences of the abuse and move beyond it. Remember after all, what Oedipus mother did to him is regarded as a tragedy and was condemned even in the time of the Grieks for a reason.
I could be utterly wrong on this, I'm just going on what you've said thus far, and if I'm completely off here I absolutely appologize.
I really hope you find on this sight the hope and healing you deserve, and can move beyond this into the future.