I'm so sorry that this happened to you, and that the painful memories are resurfacing. It sounds like you disclosed this for the first time to your psychologist around the time you saw your brother again, which can't have made either easy, whichever came first.
In telling your psychologist, you took the first and biggest step towards healing. It may be a long process, but what matters most is that you set the process in motion. That's a huge achievement.
Some days will be harder than others– glad you came here on a hard one, and always happy to chat more.