Need Help! o Addiction?

It doesn't interfere with my life, at least not much. I don't have a GF (I've only had one and I must say she was enough for me for a long time-I never had a girlfriend in college and I find asking girls out difficult anyway) so that's not an issue. I don't spend hour compulsively on it unless I'm home alone at night and don't have school the next morning (even then 2 hours is a lot for me) . I don't save the smut on my computer, I only watch streaming video and look at pics and then I delete the history and all of the cache files, cookies, etc. I go weeks and even months without it, but then I'll hit a "trigger" and I just spiral downwards (example: today I was reading an article about French President Nick Sarkozy going to Egypt with his GF who is a model; I decided to Google her picture to see what she looks like, got a bunch of nudie pics back, and I'll leave the rest to your imagination). I've been trying to stop for 3 years. What can I do? I feel so helpless, so out of control