I don't know if you're addicted to porn or not. It sounds like you've had some "real life" encounters with guys so I'd say that you're probably not overly dependent on porn. Young guys watch a lot of porn. At least I did. I still do sometimes. As I said to someone earlier, a nice wank with some good porn can be such a cup of hot cocoa with marshmallows in front of a roaring fire on a cold night, ya know?
You don't know any other gay people who love being dominated? Really? I'm versatile so I don't care which end is up as long as someone's (mine, or his, or his, or his, or his...) package is delivered. But I have known many men who only want to be dominated (the "this is my first time" crowd to "Sweet Polly Purebred lashed to a St. Andrew's Cross" crowd, from sea to shining sea). Even if you don't want to carry it this far, there is a whole subset of the gay sex crowd who love to dress in lacy underclothes, panty hose, even high heels and then get pounded twelve ways to Sunday.
Whatever your flavor, you're not alone in your desire.
There nothing wrong with taking the passive role. Think of your dick as a barometer that tells you what turns you on and pay attention to it. If being manhandled is what turns you on, you're well ahead of a lot of guys who don't know what they want (or can't be honest with themselves about what they want in bed, in the elevator, in the department store dressing room, etc.).
There's no shame in this lovey. Lay back and enjoy the thrashing.
Just make sure the guy you're with knows your limits. It's all well and good to be manhandled, but abuse is another beast altogether.