I think many, many men deal with porn addiction to some degree.
It's an insidious addiction, because every 'session' starts so innocently, like "hmm, I wouldn't mind seeing a little T & A". Then before you know it, 45 minutes have passed and you're like "wtf did I just do with the last hour of my life?" Just one more video...one more video. It's so easy and accessible.
I've watched porn on and off since I was about 14. It's gotten to the point where I am almost completely desensitized to it. To an extent I think it even desensitizes you to actual sex. I still love sex of course and 'perform' just fine, but it's like half the time I have sex I'm fantasizing about some porno thing. I have a beautiful naked chick in my lap blowing me and I'm still thinking about some porn scene I saw?!?! That's not normal.
I used to be RACKED with guilt about it, but one day I just sort of gave in and said "fvck it, I'm tired of feeling guilty for this, every guy does it, and I'm not looking at anything sick or perverted". I think they key to getting away from it, is, like speakeasy said, having a life that does not revolve around the computer. Trust me, having a gf or regular sex doesn't change a thing. You gotta have more social things to take up your time and be constantly involved with something. Idleness is the killer.