The Morning After (1986)

Alex Sternberg (Jane Fonda) wakes up with a fierce hangover and no memory of how she ended up in bed next to a dead man. She's convinced that she's had another blackout and stabbed the now-deceased stranger (who eerily keeps reappearing). To make matters worse, her only support, Turner Kendall (Jeff Bridges), is an ex-cop and recovering alcoholic who's largely unsympathetic to her plight.