It matters. It matters SO much. It matters more than anything else they do or ever did for you.
You were ten years old when this first happened and nobody protected you. You were 16 years old when they found out and they protected your brother and they protected themselves. They did not protect you. They did not help you. They did not support you. They did not help you process any of the trauma of 6 years of sexual abuse at all.
They protected themselves and they protected him.
To listen to you, to support you, and to look after your interests in this would have meant sacrificing their own views of a happy family and also jeopardized your brothers future.
Instead they chose to sacrifice you.

You are not the only person this has happened to. Mothers and fathers all over the world have sacrificed their daughters in the same situation. My mother did too. They don't necessarily do it because they are bad people. Maybe they do it because they are just weak. Because they don't want to "rock the boat". Because they have too much to lose.

It was your basic human right to be protected, to be cared for, and to be loved. They didn't do it. More than that, they expect you to deny your own experience and reality and act as if nothing happened.

Your brother had a choice of whether to sexually abuse you or not. He chose to abuse you.
Your parents had a choice to protect your brother and themselves or to protect you. They chose to protect your brother and themselves.
Your choice is an awful one, and it is a terrible, terrible thing that you have been put in a position of having to make it. You have the choice to either protect yourself, honor yourself, care for yourself, do whatever is right for you, or to deny your own self and pretend nothing ever happened. The awful cruelty of that is that YOU then get put in the position of "breaking up the family". YOU get put in the position of "hurting everyone".
It is so, so wrong. You were the one that was most hurt. For years and years. And then for years and years more when you were forced to pretend nothing was ever wrong.

I am so very sorry for how much your family has hurt you.