I vote depression. You usually accomplish a great deal at a high energy level, so this exhaustion is a manifestation of depression, and who's surprised, you're friggin' bipolar. On the other hand, since every Jew needs at least two opinions on any given topic, maybe you just need a rest from all these deals and energy levels. That isn't laziness, though, it's wisely taking a breather. How long ago did you stop Effexor? The "laziness" could be a manifestation of a subtle withdrawal effect that will end in time.