In My Sleep (2010) on Netflix

Plot summary

A sleep disorder called parasomnia makes Marcus do things at night that he cannot recall the next day. He comes to in a cemetery and cannot say how he arrived there, and because one-night stands are his way of escaping his problems, he joins a Sexaholics Anonymous group, where his sponsor Derek helps him. Then he wakes with blood on him and a blade at his side as officers knock at his door. He hides the evidence, and they tell him that Ann, the wife of his closest friend Justin, has been stabbed to death. Calls he cannot trace leave him feeling watched, so he sets out to learn what he does after he falls asleep.