For anyone who doesnt know it, drug addiction affects exacly the same reward systems in the brain. Here is one study about it:
The situation is complicated by the fact that orgasm itself creates a drug-like high. Dutch scientist Gert Holstege observed, while viewing scans of men ejaculating, that the scans reminded him of scans of people shooting heroin. ("Brain activation during human male ejaculation"
Brain activation during human male ejaculation. - PubMed - NCBI) Masturbation to porn is a double neurochemical hit: the rush of watching extreme material and the reinforcing rush of orgasm, both of which rapidly consolidate learning--i.e., wiring in the synapses.
This means that sex can be used like a drug to get highs. Same high you have on alchool and heroine. So as you see the sources of urges are exacly the same, for example wish of you who were on drugs, when you got the urge or when you sudenlly knew you have the oportunity to get the drug or alchool, what did you felt?
Did your heart beat rapidly?
Did you felt a warm feeling passing trought your brain and you fellt a ahhhhhhhh at the same time?
Did your hands started to shake?
Did you felt the sense of "its to late to avoid this"
If so, then you had the same symptoms that the one´s with sexual addictions have.