Meditating When Demotivated
If you find some motivation then there are worldly practices to cultivate motivation.
 When the beginners enthusiasm wore off I just googled how to get motivated. Like how to keep to a schedual. You can trick yourself. You just schedule a sit for only 2 minutes. That's easy to actually do and then when you sit you often will have more momentum past 2 minutes. Then you keep doing it and grow a habit and gradually increase your time. This is just an example. There are different ways to be unmotivated.

You can chant up some motivation. 
   Read inspirational quotes over and over.
   There are all kinds of little practices.