I often read that it's a waste of time waiting to feel motivated, but to focus on commitment. You don't need to feel motivated, just commit to behaving as if you are.
I've lost my mojo for the gym recently, so today I decided to go looking for it; at the gym. If I know anything it's that you don't find your gym mojo on the sofa.
Now I just to apply the same logic to my paperwork pile!