Welcome back to the Wefugees community and thank you for reaching out to us.
First of all, I am sorry to hear that your visa application got rejected. As you mentioned already, you either need to file a remonstration or an appeal at the administrative court in Berlin now. If I am not mistaken, you will have only 4 weeks for this. After that period, a new application is the only option. As your case sounds indeed complicated to me, I would highly recommend you to get support by a lawyer in this.
Would you agree dear @alla_fka?
All the best,