Movie from early 80s or 70s. Might have been made-for-TV, American i think.
There’s a guy who suffers from nightmares, something to do with a butterfly. He hooks up with a woman, and at one point wakes up screaming and breaks a large mirror, referring again to a butterfly.
He goes to an old woman’s house, which may be his mother’s and sees a painting of a butterfly, which he realizes is the cause of his night terrors.
The movie ends with him running out of the old woman’s’ house, breathing heavily and met by his girlfriend as he calms down. I think one of them may have driven a Volkswagen.