Hello!
Recovering addict here. Your story is very familiar (although I lack a vagina). You have a Doctorate in Porn and like any good study material it can be forgotten when you focus on other things.
My partner is amazing and sexually all a man could want - it is just that my mind was so full of different sex scenes that I thought -
a/. she must be cheating because doesn't everyone.
b/. How can I satisfy her because surely she wants a long hard fuck everytime.
c/. I am surely not big enough.
d/. She wants it more than I can satisfy her.
But in conclusion -
a/. Nope. I must learn trust.
b/. Imagine a woman telling me that sometimes she is so emotional during that she would sooner cry than orgasm and that is just perfect.
c/. Compared to what? If we started comparing perfect fits it would take years to find the right partner.
d/. Except when she doesn't, like when she is feeling down, or tired, or stressed, or just busy, or (and this I no longer secretly enjoy) is happy to just cuddle.
I learnt it takes times to clear your mind of the porn images and ideals and finding other things to fill your mind with now is important. Not just the gym, but interests which could be anything from philosophy to history to fiction to fantasy (to addiction recovery - see https://www.youtube.com/watch?v=7oFVOJf0TzY Your Brain On Porn explains the addiction process and is a good antidote to just the porn side.
(Not chat magazines or soap operas that fill the mind with insecurity stories such as too fat, too thin, too normal, too this too that), the mens magazines are just the same. Ripped abs in ten seconds, eat your way to bigger thumbs, gain ten pounds in 2 milliseconds by eating bricks.)
Just some ideas, I hope they helps. Sometimes you might want a good hard f*ck but other times I assure you, you will really love love making. Look forward to it!