Unsane (2018)

A young woman harassed by a stalker is committed against her will to a mental health institution where she must face her fears. However, the question arises as to whether what is happening to her is real or the product of a hallucination. A fascinating psychological thriller directed by Steven Soderbergh, shot entirely with an Iphone, absolutely shocking and disturbing. If you are looking for a movie full of tension and that will surprise you, this is a great alternative.