I saw this movie on HBO back in the mid-1980’s, maybe 1987.  It was in English and in color.  It was about a housewife who worked tirelessly to make a perfect home and be a perfect hostess to further her husband’s career.  One morning she gets a phone call that he has been having an affair.  She then sits in a sort of catatonic state the rest of the day until he gets home at which time she stabs him to death.  As I remember it, the movie ends with her in a psychiatric ward in a full catatonic state, although the viewer is allowed to hear her thoughts.  I have no idea who the actors were.  I also have a feeling that this was a shown-only-on-HBO movie; that it was never shown in theaters (but I could be wrong).  Any ideas would be greatly appreciated.