We have two Langhorst villages in Germany, one in the community Saterland, Cloppenburg county, Oldenburg province, State Niedersachsen. The other as part of Groß Wittensee, Rendsburg county, State Schleswig-Holstein.
Diskau could be Dissau, this village is also located in Schleswig-Holstein but about 60 miles south from Langhorst.
Some of your names you can find in Schleswig-Holstein, but not in Langhorst.
I assume your ancestor came from Schleswig-Holstein, because they emigrated via Hamburg.
The Oldenburg emigrants sailed from Bremen.
You should go to the list of Schleswig-Holstein.
Werner