Nice to hear from you again.
Along with every decision by authorities you receive a so-called "Rechtsmittelbelehrung". It contains information how, where and until when you have to file an appeal. If you want to do that, I'd recommend to get in contact with a lawyer that helps you with the bureaucracy and the procedure. It might be necessary to also file an "Eilantrag" to prevent deportation. Otherwise you could get deported before your appeal has been decided by court. But you should ask an expert to take a look at your case and to decide what's the best way to proceed.