I can relate to what you're going through, although at the moment, I'm in avoidance mode, so the feelings are not quite at the surface.

My T tells me that the reason it keeps coming back is because I haven't worked through it entirely, that there's still unfinished business surrounding it and that I need to figure out what I need in order to get some peace around it.

There's a very big difference between sharing the story of the trauma and actually working through the feelings. Perhaps you can talk to T about maybe supplementing your work with another T to help you with this specific issue.