Concerned I'm a sex addict

I began masturbating when I was about ten or eleven. Since then it has become a daily habit, at best I can go two days without it. In addition to that, I have looked at a LOT of porn on the internet. I have read pornographic magazines, read erotic stories and watching porn dvds. I find myself lusting after women a lot. Many people say it's just a phase I'm going through as a young adult, but I'm worried that it's more then that.  Now, this is just normal boy/girl and some girl/girl stuff, but overtime it has gotten more graphic.  I have found since moving to Belfast to attend univeristy that my temptations are growing, in addition to sex shops; I have seen websites advertising escort services. I have never used such a service, but I am scared about how badly I lack self control. I try and get a grip of myself, but I am concerned that no matter what precuations I take, I am going to relapse, or that this habit is going to get worse over time.