I think it sounds like you were worried about your grandson, and the worst thing you could imagine would be that he died. When you disociated I think you probably believed that the worst had happened. A new birth in the family is a stressful time, I think you just cracked a little bit. I really hope your son and daughter in law can understand this, and not stay mad at you about it.

I've sometimes said things that weren't true, though I obviously believed them at the time.