For me, 'art block' is a combination of lack of inspiration/drive, and/or everything I do try to draw turning out wonky. Sometimes it's one or the other, sometimes it's both.
I sometimes really struggle to picture what I want a finished piece to look like. If I'm working on a comic page, it'll usually be the initial panel layout which stumps me. Sometimes poses and expressions for the characters in the panels, too. It can also be not knowing what kind of colour palette I want, what the environment design is supposed to look like, any number of those kinds of issues. I get around this by spending more time trawling through references, colour picking, etc until they jump-start something.
The 'wonky drawing' aspect is irritating, but it's also an unavoidable part of improving as an artist, so I just power through it. Something which helps if it's particularly bad at any given time is to use a 3D pose program and sketch over the top of the model I've posed for each panel. It's tedious, and way more time-consuming than freehand drawing, but it helps me keep pace with my comic updates when my hand doesn't feel like it's connected to my brain anymore.
I can also suffer from a dearth of actual creative drive, where I really don't want to do anything... But I have basically no comic buffer left since I combined a bunch of pages before changing my update schedule, so I don't have a choice in that regard anymore! Gotta just draw anyway, whether I feel like it or not!