Porn is toxic pleasure. It's insidious because it is 1) so commonplace and easily accessible, 2) very pleasurable and addicting, and 3) you don't "see" the damage it is doing until it is already done.
YourBrainOnPorn is a great website.
I've been watching porn since I was about 14 off and on, and those pathways are so engraved into my brain that the only way I can reliably abstain is to set written goals for myself (30 day, 90 days, etc). It's easy once I'm past the first week, and I feel so much healthier mentally. I don't obsess about it, I don't need to jack off very often, and I naturally just think about sex with my girlfriend when I'm horny. Sex itself is much more pleasurable as well when you are totally focused on that REAL woman in front of you.
Porn is one of the banes of American civilization.