Gummo left me disturbed and I couldn't sleep the night I watched it...
Happiness with Phillip Seymour Hoffman was absolutely disturbed too...offensive even...I was forced into watching it and I hopefully will not have to watch it again.
I'm not easily bothered either...if you're looking for some jarring, weird, uncomfortable and uneasy films I'd watch both of those.
Edit: another reason these films left me so bothered was b/c they are not some slasher/gore genre type of movies with lots of blood and physical pain...it's more mentally bothersome.
Gummo dispite it's lack of a storyline is a pretty good critique of society in white trash (aka Trump supporters) in lower class communities.