| I agree that taking a day off might help - you will want to pick up the bass the next day.
You said that your usual routine is like going through the motions. Develop a new routine, or change something about your usual one. I personally don't have a practice routine. I just play whetever strikes my fancy, or if I'm learning a specific song or something I'll practice that. If it gets boring, or if my hands stop cooperating, it's time for me to put down the bass and come back an an hour.
Here's something I picked up from my double bass studies. If a certain thing gets boring - like a C major scale - change it around somehow. Change the rhythm; go from 1 down to 5, then 7 down to 4, etc.; play notes more than once; add vibrato. You can do anything to make a routine or exercise more interesting. My teacher would say, "Okay, now that you've played through this exercise, split all the notes in half - play a half note as two quarters, play an eighth as two sixteenths."
Or maybe you could do part of your usual routine one day, then the other part the next day, and alternate.
Okay, those are my suggestions. Hope that helps. | 
