Buried alive and kept alive??


I canít quite remember the plot of the film but at the end a woman buried a man with a drip and said she would keep him alive for as long as he wanted and that if he wanted to die he had to take the drip out himself.
I remember enjoying it and really want to watch it again. I just donít know what itís called.
Hopefully someone here will know it.

I have considered the ones mentioned above. Oxygen (1999) also comes to mind, but I feel like the plot discrepancies are too significant, it must be something else.

I even remembered an episode of Monk where is he buried alive in the coffin. And he hallucinated about his wife Trudy where she saying something about to live or die...
Maybe u mix it for a movie 😉