In a similar vein, do you have enough control over your own schedule to block out a day or two to lock work outside and tackle your stuff? Maybe even an afternoon? I have fallen off the GTD wagon more than once, and taking a step back to "start over" has usually helped me a great deal.
There is an interesting piece in the out-of-print "GTD Fast" audio program where David walks up the various levels of focus from someone's point of view. At one level there are things to do, but at another level those things shouldn't be done, in order to do other things for growth and change, etc. Who can you hand things off to? Who should you approach about getting an assistant or finding other ways to lighten the relentless workload? Who can you groom now to move into a position that does some of the work you do now?
Go through your stuff, get as much clarity as you can, and start pruning.