It's an excellent movie with monumental acting and not just from Bruno Ganz (who is from Switzerland) as Hitler. The Goebbels family and Albert Speer (the Minister of Armaments and Wartime Production) are well portrayed too. The scene where Magda Goebbels kills all her six children one after another ("to spare them of a Germany without the Führer") is heart-wrenching. And there is a great "father & son"-type scene where Speer divulges to Hitler that he has been ignoring his orders of scorched earth and demolition for Germany for months "because there will be a Germany after the war". And Hitler just says tiredly "well, you better catch your plane then". (Speer is also the one to tell him in that scene "that the German people will expect their Führer to fall in Berlin with his armies, not in some mountain resort" when Hitler briefly toys with the idea of leaving Berlin and asks Speer what he thinks about it.)
The particular scene of the dictator freaking out is when Hitler is told that all his fancy plans about counter-offensives have failed because none of the "armies" he still believes to command has the logistic means anymore for a counter-attack. After he is told, he sends out everyone but his closest aides and flips. "That was an order!!!!" he yells and then switches gradually in a depressive, self-pitying mood, monologuing that the war is lost, but "don't any of you think I will leave Berlin because of that". (They wanted to fly him out, he refused.) He recounts how all the early major victories in the war were of his doing "because all you apparently learn in officers' academies is to eat with knife and fork".*** (One of the officers intervenes and says that he will not tolerate calling the German Army "Feiglinge" (cowards) after all the blood toll they have given.)
Like in much of the movie, Hitler is not depicted as a monster or some supernatural evil force, but as a broken man unwilling to see reality and torn between self-pity and a still mean and ruthless streak.
***Hitler had served in WW I as a simple soldier with some valor, but he was not regarded by the officers who knew him as anybody who should ever even get near NCO stripes. Being a simple "Gefreiter" - enlisted man - and being called "der böhmische Gefreite" (the enlisted man from Bohemia) behind his back by the generals of the German army would always be a chip on his shoulder. Ironically, a WW I German Army major of Jewish descent supported that Hitler received a medal. Hitler would conveniently forget about him in the WW I depictions of "Mein Kampf", yet wear the medal (the only one he ever wore).