Sexually abused as a child

So - between the ages of 5 and 9, I was molested and anal raped by another child, 3 years older than myself. However, I gave “consent” at the time, but only after being groomed into doing so. I haven’t been able to talk to family about it because of the shame and guilt I have felt for years, knowing that if I tell either of my parents (they’ve been split since I was 3) that they will either not believe me, or won’t rest until they find who did it. But it was my brother, and he is almost 19 now - I don’t want it to ruin his life, but it’s something I am burdened with every single day of my life. I also don’t want the fact that I was molested and raped to be ignored or disregarded due to the circumstances. In fact, I feel so passionately that this April (childhood sexual abuse prevention/awareness month) I want to organise a fundraiser within the senior part of my school (years 7-12). I haven’t told any teachers my story but I want to raise money to donate to some of the charities that could’ve helped me when I needed it. But I am hesitant to share the fact that I was abused - I attend a private school, am 15 and don’t come from a wealthy family at all, so I’m scared others will judge or think its stereotypical. But it’s something I feel I need to share - just the fact that I was sexually abused and that this is a serious issue that doesn’t just affect children overseas, but the girl you see in your classes every day. Does anyone have anything to say, advice, or input? It’s terrifying putting this online, but thanks to anyone who has anything to say.

Edit:

Wow. I am so overwhelmed by the response. Thank you so much to everyone, your advice means so much. I don’t know how to reply anonymously but I thank and appreciate every single one of you. ❤️❤️