While your brother's age at the time might suggest that he may not have understood the severity or consequences of his actions, it does not change the fact that what happened to you was not consensual and has impacted you. It's essential to remember that regardless of intentions, engaging in sexual activity with a sibling or family member at a young age can have a long-lasting impact on a person's mental, emotional, and physical well-being.But when he started I was only 6yesrs old but he was only 9 years old. He didn't know either.
It's common for survivors of child sexual abuse to feel like they should have or could have done something different or to feel invalidated about their experience. Remember that child sexual abuse involves a power imbalance, and children are not expected to have the same understanding or ability to determine whether or not something is appropriate for their age.
It's important to seek support from a qualified mental health professional who has experience in working with survivors of child sexual abuse as they can help you understand your feelings, develop coping mechanisms, and guide you towards healing and recovery. It's understandable that you may feel confused or overwhelmed, but know that healing is possible, and there are resources available to you.