Taking a break from a goal: how do you deal with burnout?

Is that the term? Burnout? I guess that's what I'm going through at the moment.

You see, I started drawing seriously in 2012 when I began my Flower project. In 2013 I joined the Drawspace Art program and completed a half of it. This year I contunued the program when one of my goals for this year was to master different shading techniques. Well, lately Drawspace lessons were mainly based on shading or, to be more percise, creating with shading. And the more I shaded the more I became tired of it. Lately it came to the condition when I intentionally delayed drawing sessions because I had to shade again.

So I decided to take a break from it. I went thought the lessons I'm to do in the near future and realized that they are the same (or at least look like it). In all of them I'm supposed to draw a more or less realistic portrait using shading. And I can't take it anymore. At first I thought I might skip several sections and go straight to section R that deals with color basics and then move on to section S when sketches are made with colored pencils. But then I thought that maybe I should do the sketches outlines and then, when I'm "recovered", complete the shading. After all, I'm sick of shading, not of drawing.

So there it is. From this point on I will be outlining only.