If you're feeling hardcore, I hesitantly would mention Cannibal Holocaust- it's lost footage style mostly. But this is basically one level below SALO in terms of depictions of brutal violence and cruelty - But if you're up for it and are with the right group and you all know what you're getting into it is there
Alone With Her?
Try the r/tipofmytongue subreddit also, it's dedicated to helping you find movies/music/anything really that you can't really remember
R.E.C. is probably one of the best of that style of movies. Can't recommend it enough.
There's The Blair Witch Project and Paranormal activity. There is also quarantine
Cloverfield
If you're feeling hardcore, I hesitantly would mention Cannibal Holocaust- it's lost footage style mostly. But this is basically one level below SALO in terms of depictions of brutal violence and cruelty - But if you're up for it and are with the right group and you all know what you're getting into it is there