My commute is long like yours, and I know the feeling about it being long and being tired at the end of it. This is why I only do the full commute only once or twice a week, and do a hybrid commute the other days. Burn-out comes easy at 60 miles a day.

Your commuter may not be the best bike for that commute. I find my road bike works better for the long commute - my Jamis Boca with saddlebags works better for the hybrid commute.