I'm sorry you've been through, and are still going through, this.
You are by no means alone, we're here to listen and support you. Well done for writing it out to us, I imagine it can't have been easy so you're really brave.
If this is still happening, or anything like it, please tell someone who can help you. You deserve much better than this, and it certainly isn't your fault. What your brother did was wrong.
Often, when we block memories out, they tend to come back at some point even stronger, and that sounds like it's what's happening with you. Is there anyone in your life you can trust to talk to about it?
x x x