I´m trying to identify this old horror movie from the 80:s (i thing), that i saw as a kid. I can´t remember the name of it, and my memories themself are vague.... but perhaps someone could help me out.

I´ll describe a couple of scenes, and maybe someone will recognise.

The movie revolves around thing young teenage guy who suffers from
nightmarish intrusions into his reality, he is being hunted by several nightmare-creauters, such as a red, powerful demon, and a scary janitor with hooks for arms. The movie is kinda B:ish, and you never know what´s real in it or not... i think the teenage boy is being called "John Doe", and i also remember this scene where a coffin suddenly stands in his bedrom.
I also have a vague memory of the boy trapping the Demon into a shutter, but im not certain... and i library scene also, i think... please, if someone recognise any of this or even better, know what movie i´m talking about.
Post the answer right here.


Thanks alot!