If I may be a bit bold to presume my advice helps in any way, I think forcing yourself to draw, especially when you don't feel like doing it is a bad idea. When uninspired, seeing work that is forced and less than your best doesn't help motivate you in the slightest. All I can say is try to find a goal you want to reach, no matter how vast or small, and aim for it in your artwork. My first little step so far this month (as I do a goal brainstorm every month to stay focused and inspired) was to work on my Brush pen skills and get better at suggesting a light source with blocks of value; that was it, and so far I ain't doin too great, but I am learning alot from my mistakes.

So just let yourself feel what you need to feel, but remember that as long as you're an artist, by simply looking at the world around you, you are improving and learning, even if only a little.