Hi,
that's overtraining. You need a better exercise program.
Sounds like you also need a better saddle. Al had good advice, but to be a bit more specific, you have a 20 min window after exercise where your body replaces glycogen at 3X the normal rate. You want to have something immediately after your workout.
Have it in a thermos in your car, whatever it takes, but immediately means immediately. I usually whip up a fruit shake.
I also take one glutamine capsule after a hard workout. It's something new I read about in Bicycling, sounded like it might work.