Things like that don't really ever leave, hon. And letting it go is often easier said than done. Particularly things said by parents, or other people we hold, or held in high regard.
Whether you're being a fool for holding on to it or not isn't really an issue, because I get that sometimes it feels almost impossible to let it go.
Buddha once said "Holding on to anger is like grasping a hot coal with the intent of throwing it at someone else; you are the one who gets burned." Whether you're spiritual or not, these words make a lot of sense. It's been my experience that holding on to rage inside over something is like a fire which keeps burning you up, and keeps you focused on parts of your life which have been and gone. Parts to which venting this rage will do little to make any difference, or to make anyone feel better about anything. All it does is keep you feeling trapped in a place from which you feel there is no moving forward.
It's been my experience that the best way to let it go is to find something else to hold onto instead. Hope, for example. Or love.
The people, and situations which caused this rage... well, they are different people now and the situations have been and gone. But that doesn't mean you can't associate yourself with new people, and make new situations which give you the positive emotions to hold onto instead. Once you do this, you may find that you learn more about what's important in life, what being you really means, and you give yourself the tools to live a better life. With this in your mind, often anger and rage lose their fire, and you become more pragmatic about them. Maybe finding a place in yourself of calm.
There's a whole world of positive experiences, and encouraging people for you to find, hon. And you never know, you may get to the point where you can find it in yourself to see that your mom may have had her own reasons for being the way she was. Things which had nothing to do with you, but maybe how she was feeling about life in herself. She may have been holding on to rage, too, and chose you as a target to vent it on.
You don't have to be like that. *hugs*