Welcome to FT indeed!

There are three distinct problems here for you, each one of which could be ok with a sympathetic person, but I doubt all three will work out:

1. Getting on the airplane (presumably in the US). As the ticketed destination is Germany, which you cannot enter at the moment, it is likely the airline will deny you boarding. Perhaps the agent will be ok when they see your intention of onward travel, but it is not guaranteed.

2. Getting into Germany. The federal police may let you in to Germany on the basis that you are self-connecting, and therefor in 'transit'. But they have the unilateral right to refuse you entry if they do not feel you meet the entry criteria and send you back on the airplane that brought you in.

3. Staying somewhere for 20 hours. Assuming you were able to get in to Germany, you could pick up your bags and sit it out in the airport. I do not believe in your circumstances that you will be allowed into a hotel.

I hope it works out for you!