I'd say that's entirely normal. I cheated on a girlfriend (sad to say, not proud of it, and I will never ever do it again) and she was the exact same way when the situation came out. She wanted to hear everything.
There was a violation of trust, and she was being secretive behind your back... You want to fill in the gaps so you're on the same page with her again. Assuming you want to continue the relationship.
I'm no expert, but you may be trying to find a way to measure the level of hurt she did to you. But in the end, you're trading off the hurt you feel by not knowing with the hurt you'll probably feel when you hear what actually happened. It's lose-lose
Now I have a question for you:
How is it even partially your fault? Maybe you could benefit from reading:
http://www.tfproject.org/tfp/showthread.php?t=97905