This is really good. here's not an ounce of waste in there and the imagery is spot on.
The vast amount that you manage to convey in the first three lines shows real skill.
I know the final strophe is meant to hint at what will come, but I'd be tempted to take a step back out of the writer's emotional interaction and consider it from the perspective of an observer. That way you could tighten the ending.
The world changed.
No one noticed.
