People will do and believe anything to defend their egos. What you seem to be saying is that your mother couldn't admit that what was happening to you was bad because it might mean admitting that she had been a bad person. Sad but not that uncommon.

That was then, this is now.

The past can't be changed, it is your past. If it had not happened, you would not be who you are. Furthermore no amount of dwelling on past grievances is going to accomplish much.

So the question is what you're going to do about it. For instance you need to understand that the default is for you to re-create your parents' situation again in the next generation. Things that you focus on you tend to be opposite on, things that you don't you become an echo on. So what is the pattern, what is your role in said pattern, and what do you plan to do to make sure that you don't pass those problems to a new generation?

Another question that comes to mind is how your outrage at what happened is affecting your life. This can range from obvious effects to subtle effects. An obvious effect could be that you steam around and want to swear at your mother. Finding somewhere private to scream might help with that. A subtle effect might be that you have been conditioned to consider women in your life to be more important than yourself This would distort your relationships, and introduce a low-level resentment (which can't readily be admitted to). Something like that might be helped by making a point to stake out and own your own space on some key issues.

I'm not saying that either of these is happening, only that they are the kind of things that can happen. As you should know, I have no clue what the current effects of your upbringing are. However I can say that dwelling on the past is usually counterproductive. Until you can frame issues in terms of the present and future, you're missing the potential useful lessons in what has happened.

Cheers,
Ben