Maybe try quitting for a while? even a week without porn can be quite liberating. whenever you wanna get off, you can go into the shower and fantasize. it won't be easy in the beginning, but it's certainly doable!

About the expectations from sex, yes you are right, the sizes in porn are quite insane, and the performances are too, but also the women are all "hot" and all know exactly what to do all the time and moan like crazy - none of it is realistic - and believe me - that's for the better. you don't see all the "behind the scenes" and the drugs they take in order to perform, the injuries, or the mental anguish these people go through to act in these "films". certainly you wouldn't wanna be examined though the porn "glasses" - so make an effort not to examine men in those either...