I agree with Soidhonia. Writing what you recall down helps to remember it the next time, and eventually you have strong clues to work with. For instance, I was having flashbacks due to my accident, but I didn't recall them. I didn't even know I was having them, actually. But I began to write down any time I realized a glitch in my day (usually while driving in the rain.) I noted that I was driving, where I was, and if it was - raining. Each time I felt a different thought and noted it, it added to my picture. Before long, I not only knew I was flashing back, but now I know what types of things cause that, and guard against it.

The same with dreaming for me. Yes, the journaling can also tell your brain, Hey! I got what you were trying to tell me! And it, and you, move on to another point.

Go slowly though. Dragging memories out when you aren't ready can cause you to be retraumatized. As Soidhonia said, work with your T on this. Going slower can make therapy progress faster.