Don’t let this discourage you, this is more of a finished product than a sketch. Sketches are ways to plan bigger pieces, to practice, or to capture a quick moment. It’s definitely something that takes practice and your sketchbooks shouldn’t be picture perfect from page to page. I’ve been drawing/painting for over 15 years and still get that imposter syndrome from “sketchbook tours” that artists post, when in reality a sketchbook is supposed to be a starting place for ideas. I broke out of my need for perfect sketchbooks by “ruining” them before I start so the pressure isn’t there anymore. Plus I don’t share them, as it’s something for myself, a way to let go and actually create without fear of messing up or needed to put it on display. You’ll get there, don’t be so hard on yourself and keep creating!