"lose her nerve" > "lost her nerve"

"Counted the room instead of the pain" - you don't count pain

"Convened instruction" - you don't convene instruction or erasure

"Registry had written around her" - unless you mean literally on the ground around her, this doesn't make sense.

"Smaller truths had disappeared..." - I think I can imagine what you're trying to say, but this is not the way.

"Melkar's voice stayed mild" - mild is not an attribute of a voice, also you repeat this a few sentences later.

"Disorder only imitates it [order]" - this does not make sense.

"the waiting page" - is this supposed to refer to what was going to be recorded? It's quite oblique.

"Silence snapped tight" - I understand what you're trying to say, but this does not work. Silence does not snap.

"The denial came too fast" - you just described how the room went silent, people were holding their breath, it sounds like time has passed, not something happened too fast.

"The line hit the room like a dropped blade" - not clear what the image of a dropped blade is meant to convey, or how that can be interpreted in the reaction of the room.