Is there such a thing as sex/porn addiction? if you would like to cut down on masturbation and sex is this an unnatural/impossible impulse?

Two different issues: Addiction is defined as a pursuit (drugs, pornography, etc) that interferes with healthy behaviors. If you watch porn several hours a day instead of working, or interacting with family, then it is an addiction. But watching some pornography and masturbating less than 3 x a day is probably not addictive behavior. It is just being a normal guy. Do it in moderation and consider yourself normal.