Drawing SOMETHING when you can is always good, expecially when motivation is low!
Motivation can be a fickle little beast, so dont blame yourself too much if your always feeling "busy".
Blaming yourself for something that the little brainworms are making you do, just ends up with you feeling worse off.
It helped alot when I learned to accept that most days were just not going to happen, for reasons beyond my concious control, and that being mad with myself never helped. (At least when it comes to doing art) Berating and fighting myself ultimately never made the problem better, just WAY worse.
Drawing SOMETHING when you can is always good, expecially when motivation is low! Motivation can be