I love you lots, bro, and I hear your frustration. And she should be smarter, and it would be nice to have a family that helps protect you from these things.
But.
You were put in a family where spiritual growth is possible. In fact, you were put in the only family where true spiritual growth is possible - for you.
Someone here once pointed out something that's completely true, and very inspiring, if only we could always keep it in mind. Every test we face, every second of the day, when we have an opportunity to get close to hashem, to reveal hashem's glory in this world...that particular test, that particular slice of hashem's glory, has never been revealed before, could never be revealed before, in all of history - and it will never get a chance again.
You were put into this world to grow. And the growth you need to do may be something that requires rising above the situation your family has put you in. Most of us here, on some level or another, have had to do that.
Finally - you admit you're powerless? OK, then what do you have to do to make sure that you're not in a situation that requires you to be powerful?