Trying to find a novel or maybe short story where a man in the 1950s or 60s wakes up after a car accident in a future rehabilitation center. He is angry and hurts or kills someone and they treat him as if his anger is a mental illness. His primary contact is a woman unconcerned with nudity. Sex is not taboo.
The protagonist, Perry Nelson, dies in a car crash in 1939, but his mind somehow is transferred into the body of a man from the year 2086--the future man, "Gordon 755-82", had engaged in a practice called "voluntary abdication" or "suicide by willing not to live", which apparently left his body vacant for Perry's mind to take over.
He's taken in by an actress named Diana, who is unconcerned with being seen walking around nude, as per future customs (casual sex and polyamory are also the norm in this society).
He doesn't wake up in a rehabilitation center, instead he wakes up outside in a snow storm and is immediately helped by Diana. But he does later fall in love with Diana and fights one of her actor friends out of jealousy, which results in him being taken to a rehabilitation center since this type of sexual jealousy is seen as a primitive atavism.