Here are some pieces I like best. It is hard to find worthy recordings on youtube.
Gustav Mahler‘s Symphony No. 5 in G sharp Major.
Sergei Rachmaninov. Piano concertos 1 & 3. (hard to find but ask D for CDS)
also Sonata in G Minor for Cello
I know you don’t like opera but you might be swayed by this excerpt from Puccini’s Madame Butterfly ‘Un Bel de Vedremo’ (one fine day we will see).
also ‘Liebestod’ the final dramatic aria from Wagner’s Tristan and Isolde. (will help with your German). This is a very famous recording from 1952 sung by Kirsten Flagstad.