movies: Mein Name ist Bach and an old film version of the novel Friedemann Bach; which is really about Friedemann but does feature the sequence where Bach père visits the Prussian court and offers some impromptu understanding chat when asked. "Mein Name ist Bach" is actually on YouTube in its entirety with English subtitles, here. cahn, the sister featured in this movie, Amalie, is the youngest (belongs in the age group of Heinrich, was basically a baby when the Katte drama went down).

Re: historical likelihood of therapy, I agree with you, and given the importance his faith had for Bach, he probably would have said something, which, disaster ensues, etc.