1 - The main character, who I remember as a woman, is a doctor.
2 - She is in a very specific field, and as the movie expands, we learn that she is experimenting with different medications on her patients to cure a disease that she herself has.
3 - I also recall, albeit less specifically, that she believed her husband was having an affair with her sister or best friend, and at some point she comes into their ‘vacation cabin in the woods’ and catches ‘them’ going at it on the sofa. In a rage, she kills them both with an axe… I believe when this murder happens, all three are on vacation together.
American movie, not sure of the timeframe because I watch a LOT of movies but I would say from the 2000s forward. I remember the characters were played by known actors, but I can’t put faces or names to them.
I know it is not Clinical or Side Effects, and I remember it as a thriller/mystery type movie.
All help will be appreciated - been looking for this one for some time and thought why not give the folks who probably know a chance.
TIA