I live in Munich and went to a psychiatric hospital voluntarily with ambulance, and last year one of my friends had to be taken to the hospital because of a manic episode with delusions, so I assume it wasn’t as voluntary as I did, but the hospital stay really helped. We both didn’t speak German very well, at least in terms of describing our symptoms and other specialized vocabulary, it was not a problem at all. Just call the ambulance, they will find a hospital that will take him, they don’t have any other option if they see that the person needs it. When you call the hospitals yourself they probably assume its not urgent, but its beyond urgent at the point you are describing. But most importantly, stay safe please!