I've had this as a thought in my head since 1995 after I had a dream that had five parts:

1st: A person is on a planet where, if the sun is out, you will die in 30 seconds due to the intense radiation
2nd: A happy-go-lucky day at a theme park ends with a red-eyed demon that only one man can see.
3rd: A lone spacecraft flies through a hellish space, the pilot's own mind.
4th: A young man's birthday, but it's also the day he's getting married in the future; so he comes to a crossroads.
5th: Back on the planet, the man realizes he is the pilot and is still stalked by a red-eyed demon.

chapter titles are based on songs by Soundgarden.
book plot is based on "Psychosis" by Naxat Software