It doesn’t look like trash to me. You’ve got the right idea about following the contours of the form and the shading you had already done made sense. Understanding shading is really just about understanding the form. I’ve draw the basic shapes in red and all you’re doing is thinking about where the light is coming from and which surfaces are pointing towards it and which are in shadow. You are then free to apply as much or as little shading as you want based on what you want to achieve. You can add cross hatching to help build up the values, and so long as you keep the form in mind you’ll end up with something that looks believable (which you had already done. So be kind to yourself. Just as an FYI, and this is not a criticism. The suction cups normally go on the inside of the tentacles. You’ve drawn yours on the outside. Just a minor detail.