Since kazuo Umezu and junji ito has been recommended, how about some by ochazukenori? Horror mansion is still my favorite, but his other works is also great.
nakayama masaaki? Fuan no tame and kouishou radio is kind of all over the place and fuan no tame is basically a few page of some short horror and ghost occurance, might not be your liking but maybe you'll like it idk.
There's also kuro by soumatou. It's cute but hella disturbing on the side.
Shokuryou jinrou and apocalypse no toride is also a good read (though it's from two different writer but same artist), it gets ridiculous a lot of time but I still like them lol.
Kami no kodomo by Nishioka Kyoudai is also disturbing in a lot of way.
And then if you're into ero guro and creative absurd and surrealistic genre, shintaro kago is one I'll recommend. I'm not proud of it, but dude is master at twisting some random s*it into something amazing. Amazingly disturbing and weird.
I don't remember much of other (and you mentioned you read a bunch of other so I'm not sure what to recommend) but if you haven't read parasite by iwaaki hitoshi yet, try that one.