What a blitzed through means
Blitz, noun and verb, comes from the German blitzkrieg:
noun
an intensive or sudden military attack.
INFORMAL a sudden, energetic, and concerted effort, typically on a specific task.
"a major press blitz”
verb
attack or damage (a place or building) in a blitz. "news came that Rotterdam had been blitzed"
AMERICAN FOOTBALL attack (the passer) in a blitz.
From Oxford via Lexico.com