dont understand why you'd make it dark and grungy "melancholic" if you enjoy it.
anyway, grung background makes up the majority of the atmosphere and without it, it just looks like a doodle with no real effort put into it. but it does suit the grungy background, so its chilled.
progressing it further with some lighter lineweight directional lines to give it a bit more of a 3D feel, give it more body, while still keeping it grungy and dirty, would add alot to this.
as it is, the style you're working in, is pretty limited to "cute emo internet drawings"
but with some refinement, and attention to detail, could progress into something different, and better.
keep the roughness and start gathering some knowledge and inspiration from other artists within the style. you can do rough and grungy without thick black outlines and creepy characters.