I dream of working as an artist because I dream of something which inspires me beyond the mere paycheck. But I lack the confidence or technical knowledge to sell myself as an artist; how does it come so easily to others?
It doesn't come easily, to anyone. Those who lack self-doubt lack the self-critical facilities needed to improve their work to a professional level.
Some folks fake confidence, because they think they have to.
Some admit their impostor syndrome.
A very few become household names, accept that they're competent, and turn into jerks.
Keep working your art. Practice, improve, put it out in public, and eventually you will find your audience.
Face it till you make it. 
@mwlucas Thank you!
I feel like my work is okay, and potentially professional grade (there's stuff that needs improvement that I haven't even noticed yet, but getting to spot that and improve is part of the appeal of going professional right?). But I'm scared of not making enough money; I'm scared of not being able to hack the rejection when it inevitably happens.
If you go into the arts, the world is going to treat you and your craft with a baseball bat.
If you don't go into the arts, the world is going to treat you and your craft with a baseball bat.
It's gonna happen anyway. You might as well get paid.
Getting paid takes time and starts out slow. I needed two decades to go full-time, and had to learn business first.
@Leucrotta
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