Is it normal that i'm addicted to porn

Guys, I have come to the realization that i'm addicted to watching porn. I have been watching porn every night for years now, and every time I do I promise myself that it will be the last time.
Please help me, guys.
It's ruined my relationship with my girlfriend. My parents are to embarrassed to confront me when I visit them for break. So I pretend that I don't know that they know. I don't have the strength to stop. I don't want to do this the for the rest of my life.
Please suggest anything.