Protagonist(s) planning suicide movies

Better off Dead 1985

Two Days (2003)

Paul Miller, a self-described "failed actor," sets out for his final act and his ultimate role: the last two days of his life ending with his suicide on tape. He tries to reunite with old friends and family members to say one last final goodbye, all of whom attempt to coax him out of killing himself or dismiss his intentions as a joke.

I saw a British one recently . The guy employs elderly hitman to help him after his attempts fail.

Alien 3. Ripley has a Queen Xenomorph inside her and want to kill herself after her and the prison colonists kill the dog/oxen Xenomrph.

Cast Away

Chuck puts a noose on a cliff and tests it out with a tree trunk. Boy oh boy, suicide is seriously gruesome shit, I don’t know how they do it.

Groundhog Day

On the Count of Three (2021)

It's about two friends who make a suicide pact.

Taste of Cherry (1997) -- https://youtu.be/lNVA6LusW5M -- English subtitles available