A mistake people often make is waiting for motivation to come first before doing anything...unfortunately that is not how it works all the time. There are rare times when someone may get a burst of motivation, but for the most part people have to take action first, and then motivation follows afterwards.

On days when I don't feel like going to work, if I waited for motivation to arrive it just wouldn't happen. So I force myself to get up, shower, get dressed, eat breakfast, etc, and don't allow myself to think of potential reasons/excuses to not go to work. Perhaps if you just force yourself to get up and go, the motivation will follow.