I don't know enough German to translate, but perhaps you mean something like "stereotyped" or "branded" (like you said). I am guessing that you are talking about how Germans are stereotyped. e.g. English people are I get stereotyped as / branded (as) compulsive tea drinkers if they happen to make a cup of tea at 4pm. e.g. As an English person, I get stereotyped as / branded (as) a compulsive tea drinker if I happen to make a cup of tea at 4pm. ("as" is optional with "brand")

As a German

The first one is better. 'Branded' is a good expression - it's a literal translation that also works well in English. 'Put down' can have a similar meaning, but it doesn't work here. 'Getting put down' makes you think of what happens when vets dispose of sick animals!