What you are suffering is from excessive pelvic, anal and
perineal muscle usage which are involved in ejaculation. All these
muscles will go into a physiological spasm in order to help to
contract the muscles around the genitals during an orgasm and
ejaculation.
Excessive usage of any muscles will lead to cramps and any movement
(which involves the muscular movements) that involves the muscles
will then bring on pain. Such muscular aches can lasts from weeks
to months, but it eventually resolves. Try some muscle relaxants or
analgesic creams (METSAL or COUNTERPAIN - MINT) though it may
sizzle a bit, but it kills or reduce the pain.
PANADOL (Paracetamol) is also effective, 500 mg three times a
day.
WARNING: Please masturbate less frequently =P
