I had a dream about visiting horrifying alternate universes

Last week I had a dream in which I had a kind of machine that could travel to parallel universes very much like ours, but in which things were always dark and twisted. Sometimes it was obvious and sometimes it was subtle. Also, the machine worked kinda like a radio. You had to tune in to a specific "frequency".

In one universe I was in a very short corridor, with one door ahead of me. When I opened the door, there was the same thing. I was running, but there was no end to it: it just looped endlessly as I felt someone or something behind me. I managed to find my machine and leave.

In another universe, everything was normal until I decided to visit my grandparents. I went to their house and immediately went inside where I witnessed them being murdered by some maniac who had a sledgegammer or something like that. I just ran out and left again.

In the final universe I was home and the tv was on. Except it was not normal stuff. There were shows about murdering people, demon worship, and cooking shows were all about cannibalism.

I woke up after that, feeling quite disturbed.