I am deathly terrified that they will mistakenly believe that I am deluding myself into thinking that I’m good at this. That they won’t understand that I know very well how bad my pictures are.
@Sandra I can relate to this kind of fear. Sometimes I look at the way we encourage kids to share their creative work and celebrate it, and wonder why we can't keep the same culture going for adults – but I think I know why; it's the commoditisation of creative output and the pressure on adults to keep to "productive" pursuits 
But I think it'd be a better world if that were different.
I agree.
There’s also another reason, here locally (this was first noted by a Danish author, but it’s true in Sweden also): the “Jante” law, the taboo of kidding yourself that you’re “better” along any vector than the rest is so big. And, it makes sense, we wanna be all together in solidarity, work together, it’s not a race etc.
But the fear then remains that they’ll think I’m breaking the “Jante” law. Fears of taboos can make it so hard to just be free to make really bad paintings and drawings, which is fun. Or sing badly or write confusingly or whatever. 
Not to mention that it makes even harder to dare to try to make good stuff. Because doing something bad and saying “lol it’s bad but fun” is way safer in the jante-regard than reaching for good and failing.
@Sandra Yeah, I think there is an awkward divide, where it's OK to be an enthusiastic amateur going, "I know it's not the best, but I worked hard!" and it's (obviously) OK to be a bona fide creative professional, but it's really awkward to fall in the middle, trying to produce work that is genuinely good without that external tick of approval (like an illustrator job, or a book deal, or a record deal, etc.).
The "Jante" law sounds similar to what we call "tall poppy syndrome" here in Australia. Even for people who are very talented, the expectation is strongly that they're humble and never crow about their success. My mum would say, "If someone's actually any good, they won't need to tell you so, you'll already know." I don't think the tendency towards humility is all bad, but I do think it makes things like self-publishing or releasing an indie record very difficult. Even if you put in so much effort and genuinely think it's pretty good, trying to promote it to other people would feel almost fraudulent, because the taboo is so strong against trying to talk up your own work. And there's also that stigma against "failed artists" (you know, like people have this perception that self-published writers are just people whose work was too bad for "real" publishing…) and it all just combines to create a really nerve-wracking situation. Sorry for rambling, btw!
@jayeless good rambles are always welcome!
You nailed it; falling in the “zone of suck”. Like, many indie and autobiographical comics artists draw a really slack, stylized, most-people-could-do-it style. Which works great, because the art isn’t the selling point.
And some comics artists are obviously absolute masters, like Xaime Hernandez or Sonia Obeck.
The fear is trying and failing to draw well.
Which would be absolutely fine if it weren’t for “the art fear”, these imagined (sometimes real) haters, who’ll pounce as soon as they think you’re overestimating yourself.
I’m so glad I did a ready made found object (Dagny) as my first selfpublished book and am working on something similar for my second. (Just need to do day job stuff too .)
@Sandra Yes, exactly! It'd be a lot easier to bring yourself to publish work that's, like, "95% perfect" if you could expect any critiques to be in the form of well-intentioned constructive feedback… but the fear of "haters" is real. So you end up second-guessing yourself before they can find you