Mouchette is a 1967 French film directed by Robert Bresson. It's based on the Georges Bernanos novel by the same name. A poor, unlikable young teen girl deals with a terminally ill mother, alcoholic father and infant brother. This is the perfect film for those times when you need your exuberant cheerfulness reigned in and all the joy sucked out of your life. You can follow it with Bicycle Thieves and just wallow in the sadness and depression and hopelessness.
There are some clips at TCM, but I can't find anything that shows up here when I try to embed it. Maybe that's a safety feature? Limiting people's exposure to such depressing material?
Time Out calls it "a magnificent and deeply rewarding example of Bresson's stripped-down methods of cutting and framing, sound and dialogue, performance and movement." DVD Talk calls it "a devastating examination of human cruelty". FilmRef.com says, "Bresson creates a metaphor for the fractured soul. ... In essence, we are Mouchette - foundering and incomplete - seeking redemption from the misery of existence, incapable of articulating the pain -resigned to our own private hell." Ruthless Culture says the film "seems bleak to the point of outright nihilism". Rotten Tomatoes has a critics score of 87%.