Hastings is in a really bad spot, I would've skipped it in favor of just settling Nottingham in the first place, but it's not unrecoverable. I see archers and chariots in production, Horseback Riding might grant a faster return-on-investment than Iron Working, especially with a city to retake.
BUT! I reiterate my previous advice: an empire runs on its emperor. You might find copper in that hilly NE region. You might uncover iron on your very doorstep. You might have enough manpower to just march on Nottingham and take it right back. Don't underestimate the potential of mobilizing your city defenders, a barbarian city-state that close to your borders this early could devastate your empire, especially since you've lost the Great Wall! Without such protection from the savage hordes, you need to expand early, and as often as your budget will allow. Otherwise, the Germans will head east as soon as they are able, and you'll be destined to a footnote in their history books as "those guys with funny northern accents who got annexed when we founded Judaism."
