Take another look at just the phrases about knowledge and perception in this snippet:
I don't know why, but I feel like I just swallowed a whole egg, shell and all. I can tell something bad's happened – I'm not stupid – but no one has told me yet. I don't know. If my Dad is dead, we just won't live anymore.
First person narrators have limited information. We can use this fact to emphasise the stress of not knowing what’s happened. Try to fold this feeling into your variation, even if you just use the phrase “I don’t know”.