I know you got some answers on Discord, but I wanted to add that it seems you're getting caught up in a bit of confusion between being able to draw something, and being able to draw well, which ends up being a particular point of contention amongst many students. Basically, because they know they can't draw things in a way that would meet their expectations, or satisfy what they wish they could draw right now, it feels wrong, and bad. The act itself, as though it is something you shouldn't be doing. That is not at all the case.

As explained in this section from the lesson material, not being able to meet an arbitrary set of expectations does not mean that you're not ready to try, and that is all we ask of you for the 50% rule. It's still scary, but that's largely the point. The 50% rule forces us to face the frustration and unpleasantness that comes from not meeting our own expectations, to gradually cut away at the expectations and break them down - because though they hold a lot of power over us initially, those expectations aren't actually based on anything real, because we ourselves invented them, and we ourselves are still beginners who don't know anything about what we should be expecting of ourselves.

Just remember why you started. Do you started to do comics? To work for a company that owns you favourite franchise? To ilustrate a child book?

So draw something that made you decide start drawing, but do it without the weight of being good, just do it cause you like it. And keep it. One day you will enjoy compare your actual level to where you started.