Well, first off, not every guy watches porn. Preferences vary. Some of us prefer our imagination.
Porn addiction is possible. What an addiction is, is a subjective thing. The most common definition is something that takes up so much time it interferes with your life. Is porn like that for you? Many adult men also look at porn. You may get used to it. I don't think it is a phase so much as a preference for erotic stimulation.
"I don't believe in magic. But I do believe in interpreting coincidence exactly the way you want to." -Sherman Alexie