Shoot, it's perfectly normal.
When i hit clomid, i can't get motivated to do shit. This summer has been pretty rough on my as far as personal stuff going on, and i haven't worked out the past 2 months that hard at all....
But it's all about sticking with it. If you need to, take a little break from it and hit it up hard when you come back. It's normal to get burned out with something after a while, it happens.
There is more to life than working out/BB unless you're pro. Just realize the priorities of your life, and exactly what working out means to you.
I realize it's the greatest thing ever, since it helps my self esteem a ton, and it's something i can feel good about. School comes easy for me, so i don't really think that's all that great, but working out i have to bust my ass for all the time, and it definately pays off.
Oh yeah, just get some hot ass, that always makes me feel better