Meditate more often and seriously, and seek out the root cause of this addiction by pondering on why it exists.
Talking about it to someone professional can also help there.
There may very well be some kind of anxiety within you, which porn and orgasm can be a way of curing anxiety with.
The more you meditate, the less anxiety you will have - thus less need of curing it with porn or other things like alcohol etc. which are more destructive and less healthy ways of dealing with it.
With all addictions; be it alcohol, drugs, porn etc. it's always better to think "I don't really need to do this" (which is TRUE) rather than simply "I forbid myself from this" (making into something of a forbidden fruit, and thus more appealing).
A side note here on drugs, which I think is extremely key to remember - we in Joy of Satan are against drugs,
not because we are against having fun in life, but because we are FOR having fun in life.
The less alcohol and drugs being used, the better are also the conditions for having fun, since the essential things needed for having fun is a good health and a balanced, focused and organized mind.
JoS provides the knowledge for obtaining exactly this, and I guess that is also a reason for the name Joy of Satan.