Hi, honey. I'm a BW, too, but I have some advice for you about the timeline.
If you are worried about turning it into an interrogation, you can always write down your questions (to get them down exactly the way you want them to be) and then hand him the list and have him read the questions and tell you the answers. His answers will, invariably, bring up more questions. If you are able to go back and forth in a discussion, great. If not, you can write another list and have another go at it.
Some people choose to ask the questions and look at the timeline with a marriage counselor present. I don't know if that would help you or not.
But gently, honey, there's nothing wrong with having an emotional reaction to a harsh truth. What happens if you do fall apart? He has to deal with it, ok? You are entitled to fall apart when you are dealing with this stuff. Stuffing your emotions in order to keep it together won't help you or the situation. You have to feel the feeling and walk through the hurt, unfortunately. There's no healthy way around that. ((((sadwife))))You can call me NIK
"If you carry joy in your heart, you can heal any moment."
- Carlos Santana