After over 12 yrs of practice, I lost my drive as well. Why ? Well, getting older, different priorities, the hard as hell tatami mats seem even harder. But really becuase of the instructors - I don't feel any of them can "move" me forward in my training anymore. They can't bring me up to the next level and I feel stuck. I have outgrown their abilities - and this isn't braggin' or anything, it's just the way it happens to be.
If this is the way you really feel, then it may be time for you to move on. You may want to try a different style. I don't know. Are you in to Aikido for life? Or do you want to move on altogether? If you stay in, a change of schools may be just the challenge you need. But always hold onto what you learned at your first dojo. All Aikido styles, though different, are still the same in essence.