I don't have many memories either, and the few I have are very disjointed, I don't always know the ages unless they happened at school. Most of my memories are from school, almost like that was my house. I don't know why.
It doesn't matter, though. When memories come up, and they do, usually in dreams, my therapist has me handling them by visualizing myself comforting the child me in the situation. Telling her things are okay and that she is loved and she deserves love. I re-imagine the situation with adult me in the picture also, and I praise and comfort the little me. It sounds totally insane, but it's really helping me to work through my emotional baggage.
Even without memories, sometimes I talk to imaginary little me in everyday life, and tell her what a good job she is doing with very mundane tasks. One of these days I'll either turn into a legit crazypants, or I'll slowly start to feel better! Either way works, I guess, lol!
I've gone off track, but my initial point was to agree that all the memories don't have to exist in order to work on fixing the now.