Happiness is a 1998 American black comedy film written and directed by Todd Solondz, that portrays the lives of three sisters, their families, and those around them.
Cast includes Jane Adams, Elizabeth Ashley, Dylan Baker, Lara Flynn Boyle, Ben Gazzara, Jared Harris, Philip Seymour Hoffman, Louise Lasser, and Jon Lovitz.
I haven’t watched this yet, but your description matches my expectations. Thanks