I am in a similar situation in that I often feel like I'm doing things wrong and could be reprimanded at any time. This is not how work is supposed to be structured, even by ghouls. Good managers give clear expectations, and regular, informal feedback. This actually makes their jobs better, because when people are comfortable they don't hide problems - which is an action that can lead to huge failures later on.
So, I think what you're experiencing is common, and is a byproduct of poor management. I have had good managers and the difference in work culture is astounding. One can be confident at work with good management.
Otherwise, you just have to assume you're doing a good job, or you can actually just ask for clearer definition of goals and tasks, which might help.