Riding in the drops does put more stress on your body but 20 miles isn't that extreme. Maybe you need to stretch out a little before your ride, or during your ride to keep the blood flowing throughout your whole body? Whenever I get shooting pains during a ride I take a minute to stretch, loosen up and walk it off and they usually don't come back.
As for your male areas, you may need a better seat, or again you may need to make sure that blood is flowing where it needs to... Sitting in one position for too long ain't good for any part of your body.