Banish the mold and mildew of your shower curtain by purchasing a new one and installing it today. It’s much easier to do this than to wash your old one, especially if it’s been exposed to mildew for a long time.
(Alternately, you can try to clean your shower curtain with mildew remover. Some curtains can also be washed. So you may want to try these methods before buying a new one.)